Mechanically Adaptive Polymers Constructed from Dynamic Coordination Equilibria

Designing materials capable of adapting their mechanical properties in response to external stimuli is the key to preventing failure and extending their service life. However, existing mechanically adaptive polymers are hindered by limitations such as inadequate load-bearing capacity, difficulty in achieving reversible changes, high cost, and a lack of multiple responsiveness. Herein, we address these challenges using dynamic coordination bonds. A new type of mechanically adaptive material with both rate- and temperature-responsiveness was developed. Owing to the stimuli-responsiveness of the coordination equilibria, the prepared polymers, PBMBD-Fe and PBMBD-Co, exhibit mechanically adaptive properties, including temperature-sensitive strength modulation and rate-dependent impact hardening. Benefitting from the dynamic nature of the coordination bonds, the polymers exhibited impressive energy dissipation, damping capacity (loss factors of 1.15 and 2.09 at 1.0 Hz), self-healing, and 3D printing abilities, offering durable and customizable impact resistance and protective performance. The development of impact-resistant materials with comprehensive properties has potential applications in the sustainable and intelligent protection fields.

Mechanically Robust, Durable, and Multifunctional Hyper-Crosslinked Elastomer Based on Metal-Organic-Cluster Crosslinker: The Role of Topological Structure

Polymer materials formed by conventional metal-ligand bonds have very low branch functionality, the crosslinker of such polymer usually consists of 2-4 polymer chains and a single metal ion. Thus, these materials are weak, soft, humidity-sensitive, and unable to withstand their shape under long-term service. In this work, a new hyperbranched metal-organic cluster (MOC) crosslinker containing up to 16 vinyl groups is prepared by a straightforward coordination reaction. Compared with the current typical synthesis of metal-organic cages (MOCs) or metal-organic-polyhedra (MOP) crosslinkers with complex operations and low yield, the preparation of the MOC is simple and gram-scale. Thus, MOC can serve as a high-connectivity crosslinker to construct hyper-crosslinked polymer networks. The as-prepared elastomer exhibits mechanical robustness, creep-resistance, and humidity-stability. Besides, the elastomer possesses self-healing and recyclability at mild condition as well as fluorescence stability. These impressive comprehensive properties are proven to originate from the hyper-crosslinked topological structure and microphase-separated morphology. The MOC-driven hyper-crosslinked elastomers provide a new solution for the construction of mechanically robust, durable, and multifunctional polymers.

[Fibrocartilaginous mesenchymoma: a clinicopathological analysis of four cases]

Objective: To investigate the clinical, radiological, histological and molecular features and the differential diagnosis of fibrocartilaginous mesenchymoma (FM). Methods: Four cases of FM diagnosed in the Department of Pathology, the Sixth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine from 2020 to 2022 were analyzed. Related literature was also reviewed. Results: Case 1 was a 10-year-old girl with bone destruction in the sacrum and L5 articular processes revealed by CT scan. Case 2 was a 7-year-old girl with an aggressive lesion in her right distal ulna. Case 3 was an 11-year-old boy with a lesion in the metaphysis of his left proximal tibia. Case 4 was an 11-year-old boy with bone destruction in the distal portion of a radius. Microscopically, the four tumors all consisted of numerous spindle cells, hyaline cartilage nodules, and bone trabeculae. The hypocellular to moderately cellular spindle cell component contained elongated cells with slightly hyperchromatic, mildly atypical nuclei arranged in bundles or intersecting fascicles. Benign-appearing cartilaginous nodules of various sizes and shapes were scattered throughout the tumors. There were areas mimicking epiphyseal growth-plate characterized by chondrocytes arranged in parallel columns and areas of enchondral ossification. The stroma was rich in mucus in case 1. Mutation of GNAS and IDH1/IDH2 and amplification of MDM2 gene were not found in any of the three tested cases. Conclusions: FM is very rare and tends to affect young patients. It most frequently occurs in the metaphysis of long tubular bones, followed by the iliac-pubic bones and vertebrae. FM is characterized by a mixed population of spindle cells, hyaline cartilage nodules and trabeculae of bone, without specific immunophenotypes and molecular alternations. As a borderline, locally aggressive neoplasm, surgical removal with a wide margin is generally the treatment of choice for FM.

[Establishment and application of animal models of pulmonary alveolar proteinosis]

Pulmonary alveolar proteinosis (PAP) is a rare respiratory disease, but this disease has slow research progress. Animal model is an effective tool for basic research. Current PAP animal models are based on the main pathogenesis of granulocyte-macrophage colony stimulation factor (GM-CSF) signal disorder and environmental homeostasis imbalance in the alveoli. Application researches focus on the treatment strategies of PAP. The existing PAP animal models cannot fully reflect to the development of human PAP, which should be further developed and improved to provide the basis for clinical practice.

Direct alkylation of N,N-dialkyl benzamides with methyl sulfides under transition metal-free conditions

Amides are a fundamental and widespread functional group, and are usually considered as poor electrophiles owing to resonance stabilization of the amide bond. Various approaches have been developed to address challenges in amide transformations. Nonetheless, most methods use activated amides, organometallic reagents or transition metal catalysts. Here, we report the direct alkylation of N,N-dialkyl benzamides with methyl sulfides promoted by the readily available base LDA (lithium diisopropylamide). This approach successfully achieves an efficient and selective synthesis of α-sulfenylated ketones without using transition-metal catalysts or organometallic reagents. Preliminary mechanism studies reveal that the deprotonative aroylation of methyl sulfides is promoted by the directed ortho-lithiation of the tertiary benzamide with LDA.

Alkali-amide-catalyzed divergent sp2 and sp3 C–H bonds alkylation of alkylthiophenes with alkenes

Divergent sp² and sp³ C–H bonds alkylation of alkylthiophenes was achieved selectively with LDA and KHMDS catalysts, providing not only atom-economical synthesis approaches but also some insights in the different behaviours of the alkali amides.

Deep small RNA-Seq reveals microRNAs expression profiles in lactating mammary gland of 2 sheep breeds with different milk performance

Micro ribonucleic acid (miRNA) is a type of noncoding RNA, and it has been revealed to play important roles in the activity of the mammary gland (MG) in some species. However, the function of miRNAs in MG of sheep is poorly understood. In the study, Gansu Alpine Merino (GAM; n = 9) and Small-tailed Han sheep (STH; n = 9) with different milk production traits were investigated. Microstructures and the expression profile of miRNAs of MG tissues at peak lactation were studied. Mature alveolar lumens of MG in appearance were larger in STH than GAM. The expression levels of CSN2 and the content of rough endoplasmic reticulum were also higher in STH ewes than GAM ewes. A total of 124 mature miRNAs were expressed, and 18 of these were differentially expressed between the 2 breeds. The KEGG analysis results showed that the targeted genes of differentially expressed miRNAs were mainly involved in some metabolic pathways and signaling pathways related to MG development, milk protein, and fat synthesis. The findings in the study can improve our understanding of the roles of miRNAs in the development and lactation of MG in sheep.

Alkyl lithium-catalyzed benzylic C–H bond addition of alkyl pyridines to α-alkenes

The alkyl lithium catalyst successfully achieved the benzylic C–H bond addition of alkyl pyridines to α-alkenes, and displayed distinct selectivity from those of transition metal catalysts.

[Follow-up of people living with HIV/AIDS by primary health care institutions in rural area of Jiangxi province]

Objective: To understand the current status of follow up of people living with HIV/AIDS by health service at grass root in rural area of Jiangxi province and related factors, and provide references for the promotion of the follow up by grass root health service. Methods: People living HIV/AIDS aged ≥18 years and diagnosed before 31 December 2017 in 6 townships of Xinjian, Yushan counties and Guixi city were included in the study in Jiangxi province. They had been followed up for more than one time after the first epidemiologic survey. The information about their demographic characteristics and HIV infection status were collected by using self-designed questionnaire. Univariate and multivariate logistic regression analyses were conducted to identify the factors that influencing the acceptance of follow up by grass root health service. Results: Of the 373 surveyed HIV infected subjects aged (53.06±16.15) years, 261 were males (70.0%, 261/373). Among the surveyed subjects, the illiteracy and people who received only primary school education accounted for 54.7% (204/373). The rate of follow up of the HIV infected subjects by grass root health service was 55.8% (208/373), and those through heterosexual contact were 58.5% (190/325). The multivariate regression analysis showed that the acceptance of follow up by grass root health service was higher in those who were farmers (OR=7.36, 95%CI: 2.52-21.45), had family support (OR=16.01, 95%CI: 2.25-49.73), didn't worry about discrimination (OR=12.97, 95%CI: 4.75-35.42), trusted health care provider (OR=5.07, 95%CI: 2.19-11.76) and showed AIDS symptoms (OR=10.58, 95%CI: 2.25- 49.73). Conclusions: The performance of follow up of people living with HIV/AIDS by grass root health service was well, suggesting it is a feasible management model. Being famer or not, family member supporting or not, worry about discrimination or not, trusting health care provider or not and showing AIDS symptoms or not were the main factors influencing the acceptance of follow up by grass root health service.

Health-related quality of life of patients with intermediate hepatocellular carcinoma after liver resection or transcatheter arterial chemoembolization

BACKGROUND

The aim of our present study was to compare quality of life (QoL) between intermediate-stage (BCLC-B) HCC patients who had undergone either liver resection or transcatheter arterial chemoembolization (TACE).

MATERIALS AND METHODS

A total of 102 intermediate-stage HCC patients participated in our study, including 58 who had undergone liver resection and 44 who had undergone TACE. Baseline demographic characteristics, tumor characteristics, and long-term outcomes, such as tumor recurrence, were compared and analyzed. QoL was assessed using the Short Form (SF)-36 health survey questionnaire with the mental and physical component scales (SF-36 MCS and PCS). This questionnaire was filled out at HCC diagnosis and 1, 3, 6, 12, 24 months after surgery.

RESULTS

For the preoperative QoL evaluation, the 8 domains related to QoL were comparable between the two groups. The PCS and MCS scores were significantly decreased in both the TACE and resection groups at1 month after surgery, and this decrease was greater in the resection group. These scores were significantly lower in the resection group compared with the TACE group (P<0.05). However, these differences disappeared at 3 and 6 months following surgery. One year after surgery, the resection group showed much higher PCS scores than the TACE patients (P=0.018), and at 2 years after surgery, the PCS and MCS scores for the resection group were significantly higher than those for the TACE group (P<0.05). Eleven patients (19.0%) in the resection group and 17 (38.6%) in the TACE group suffered HCC recurrence (P<0.05). Univariate and multivariate analyses indicated that tumor recurrence (HR=1.211, 95%CI: 1.086-1.415, P=0.012) was a significant risk factor for poorpostoperative QoL in the HCC patients.

CONCLUSIONS

Due to its effects on reducing HCC recurrence and improving long-term QoL, liver resection should be the first choice for the treatment of patients with intermediate-stage HCC.

TM4SF5-CTD-2354A18.1-miR-4697-3P may play a key role in the pathogenesis of gastric cancer

AIMS

Our aim is to identify important lncRNAs and mRNAs which may play a key role in contributing to pathogenesis of gastric cancer.

METHODS

Different LncRNAs and mRNAs are identified by microarray in gastric cancer tissue and corresponding normal tissues. The function and relationship of different LncRNAs and mRNAs is performed by GO analysis and Pathway analysis and made code-non-code network (CNC) by Pearson correlation coefficients (PCC). Then mRNA-miRNA relationship is predicted through mRNA-miRNA relationship software (http://www.targetscan.org). Lastly, mRNA-miRNA-LncRNA network is established for further research.

RESULTS

The expression profiles of 3732 lncRNAs showed different expression (fold change (FC)≥2.0, p<0.05) in gastric cancer tissue and normal tissue and expression profiles of 3994 mRNAs also showed different expression (FC≥2.0, p<0.05) in gastric cancer and corresponding normal tissue.

CONCLUSION

The expression of TM4SF5, CTD-2354A18.1 and miR-4697-3P is in balance at physiological conditions, however, the balance is disrupted by some situations, which may contribute to gastric cancer. GO analysis and Pathway analysis also showed TM4SF5 played an important role in proliferation, differentiation and apoptosis. Therefore, TM4SF5-miR-4697-3P- CTD-2354A18.1 may play a key role in the pathogenesis of gastric cancer (Tab. 2, Fig. 4, Ref. 30).

A PC-based laparoscopic surgery skills training and assessment system

The purpose of this study is to build a cost-effective and easy-to-popularize laparoscopic training system based on improving traditional training box. The system has the capability of objective skills assessment and the function of automatic recording of training process and results, as well as 3-dimensional coordinate tracking of instruments. The results of pilot experiment in laparoscopic-assisted grip skill assessment had been shown the system can assess the different grip ability level between the senior surgeons and junior residents. Regarding to the evaluation of training effectiveness, five subjects without laparoscopic surgery experiences were asked to perform grip training for five days to observe their training curves. According to the experimental results, the total time taken for subject 1 to subject 5 are improved by 54.9%, 52.0%, 60.6%, 23.3%, and 63.5% separately.

Mixed-spin pairing condensates in heavy nuclei

We show that the Bogoliubov-de Gennes equations for nuclear ground-state wave functions support solutions in which the condensate has a mixture of spin-singlet and spin-triplet pairing. We find that such mixed-spin condensates do not occur when there are equal numbers of neutrons and protons, but only when there is an isospin imbalance. Using a phenomenological Hamiltonian, we predict that such nuclei may occur in the physical region within the proton dripline. We also solve the Bogoliubov-de Gennes equations with variable constraints on the spin-singlet and spin-triplet pairing amplitudes. For nuclei that exhibit this new pairing behavior, the resulting energy surface can be rather soft, suggesting that there may be low-lying excitations associated with the spin mixing.

Some additional data to the occurrence, morphology and validity of Myxobolus turpisrotundus Zhang, 2009 (Myxozoa: Myxosporea)

Myxobolus turpisrotundus Zhang, 2009, infects allogynogenetic gibel carp Carassius auratus gibelio (Bloch) and is always regarded as synonymous with Myxobolus rotundus Nemeczek, 1911, since its first report in goldfish Carassius auratus auratus (L.) in China in 1955. In this study, it was comprehensively examined by morphological and molecular biological methods. The round spores of M. turpisrotundus are similar to those of M. rotundus from common bream Abramis brama (L.) in morphology; however, we detected slight differences in morphometry. The ratios of the length and width of the spore to the length and width of the polar capsule of M. turpisrotundus are usually below 2.0 and 1.9, respectively, however these ratios are always above 2.0 and 1.9 in M. rotundus. The plasmodium size of M. turpisrotundus is 600-6,200 microm in diameter and that of M. rotundus is 60-180 microm in diameter. Scanning observation showed the spore surface of M. turpisrotundus was generally pitted. Yet the surface of M. rotundus is smooth. Sequence comparison revealed the small subunit ribosomal RNA gene sequence of M. turpisrotundus did not match any published sequences of M. rotundus (EU710583, 85% over 742 bp; FJ851447, 85% over 742 bp, FJ851448, 85% over 742 bp; FJ851449, 85% over 742 bp). Moreover, phylogenetic analysis showed M. turpisrotundus clustered with the species from allogynogenetic gibel carp with high bootstrap values (100% neighbor-joining, NJ; 100% maximum parsimony, MP) and M. rotundus from common bream composed a new cluster with high bootstrap values (100% NJ, 100% MP). From the morphological and molecular biological data, we gain enough evidences to support the validity of M. turpisrotundus.

[Role of functional inactivation of p53 from MDM2 overexpression in hepatocarcinogenesis]

OBJECTIVE

This paper was to evaluate the role of p53 mutation, and p53 and MDM2 proteins expression in hepatocarcinogenesis.

METHODS

Using streptavidin-peroxidase conjugation method (SP), the expression of p53 and MDM2 proteins was observed in 61 cases of primary hepatocarcinomas (HCC) and 59 cases of corresponding paracancerous tissue, among which p53 mutations in exons 5-8 were detected in 21 cases by polymerase chain reaction single-strand confirmation polymorphism analysis (PCR-SSCP).

RESULTS

Positive nuclear p53 and MDM2 immunostainings were demonstrated in 57.38% (35/61) and 26.23% (16/61) of HCC, and 1.69% (1/59) and 3.39% (2/59) of corresponding paracancerous tissue, respectively. The expressions of p53 and MDM2 proteins in HCCs were significantly higher than those in paracancerous tissues (P < 0.01). The expressions of p53 and MDM2 were not significantly correlated (P > 0.05). There were 42.86% (9/21) mutations in exon 7 of p53 gene and no mutation was observed in exons 5, 6, 8 in HCCs and in paracancerous tissues. In cases of p53 mutations, there were 66.67% (6/9) of p53 overexpression and 11.11% (1/9) of overexpression of both p53 and MDM2. MDM2 overexpression also appeared in 25% (3/12) of cases without mutation.

CONCLUSIONS

Mutation of p53 gene and functional inactivation of p53 resulting from MDM2 overexpression play an important role in carcinogenesis of HCC. It is possible that p53 mutations and MDM2 overexpression induced by other mechanisms are involved in carcinogenesis of HCC.

New thiol and sulfodiimine metalloproteinase inhibitors and their effect on human microvascular endothelial cell growth

Matrix metalloproteinases (MMPs, matrixins) are a family of homologous zinc endopeptidases that may play a very important role in many physiological and pathological processes, e.g., the initiation of angiogenesis. Two new matrixin inhibitors were synthesized and characterized. A thiol inhibitor MAG-283 had IC(50) values of 480, 3, 280, 14, 1.1, and 2.3 nM against human interstitial collagenase (MMP-1), gelatinase A (MMP-2), stromelysin (MMP-3), matrilysin (MMP-7), neutrophil collagenase (MMP-8), and gelatinase B (MMP-9), respectively. A sulfodiimine inhibitor YLL-224 had IC(50) values of 180, 63, 4500, 210, 5.9, and 44 nM against MMP-1, -2, -3, -7, -8, and -9, respectively. Human skin microvascular endothelial cells were treated with these two compounds in culture. These inhibitors at very low micromolar concentrations suppressed proliferation of the endothelial cells stimulated by acidic fibroblast growth factor and vascular endothelial growth factor. They also partially blocked cell invasion through type IV collagen. These results suggested a correlation between the anti-metalloenzyme activity and the effects of these inhibitors on the growth and invasion of endothelial cells.

Territrem B, a tremorgenic mycotoxin that inhibits acetylcholinesterase with a noncovalent yet irreversible binding mechanism

Territrem B (TRB) is a fungal metabolite isolated from Aspergillus terreus shown previously to be a potent and irreversible inhibitor of acetylcholinesterase (AChE). In the present study, a number of binding and inhibition assays were carried out to further characterize the inhibitory effect of TRB. The results indicate that the binding of TRB (a) is much more selective than a well characterized selective inhibitor of AChE, BW284C51, (b) adopts a one-to-one stoichiometry with the enzyme, (c) cannot be undone by an AChE-regenerating oxime agent, which contrasts the ability of 8 M urea to release AChE-bound TRB, (d) is enhanced by high concentration NaCl but prevented, unless preincubated, by Triton X-100, and (e) exhibits quasi-first order kinetics with an overall inhibition constant of 0.01 nM(-1) min(-1). Together these results suggest a very different irreversible binding (a noncovalent type) from that of the covalent type, which involves typical irreversible AChE inhibitors such as diisopropylfluorophosphate and neostigmine. According to the prediction of a molecular modeling study, the distinct AChE inhibitory characteristics of TRB may arise from the inhibitor being noncovalently trapped within a unique active-site gorge structure of the enzyme. It was predicted that an optimal TRB. AChE binding would position a narrowing connection of the TRB structure at a constricted area near the entrance of the gorge, thereby providing a structural basis for the observed irreversible binding.

Design of antineoplastic agents on the basis of the "2-phenylnaphthalene-type" structural pattern. 2. Synthesis and biological activity studies of benzo]b]naphtho[2,3-d]furan-6,11-dione derivatives

Based on the "2-phenylnaphthalene-type" structural pattern hypothesis developed in our laboratory, a number of benzo[b]naphtho[2,3-d]furan-6,11-diones were designed, synthesized, and evaluated in vitro for their inhibitory action against the growth of human promyelocytic leukemia cells (HL-60), small-cell lung cancer (SCLC), SCLC cells resistant to cisplatin (SCLC/CDDP), National Cancer Institute's disease-oriented primary antitumor 60 cell-line panel, and drug-stimulated topoisomerase II-mediated DNA cleavages. Many compounds designed were found to possess potent activity in one or more of the biological tests. In general, activity found in one of the cell lines tested is often echoed in other cell lines and many also expressed substantial inhibitory activity against topoisomerase II-mediated cleavage activities. One of these compounds, 3-[2-(dimethylamino)ethoxy]-1-hydroxybenzo[b]naphthol[2,3-d]furan- 6,11-dione (8j), exhibited strong inhibitory activity throughout the entire series of test panel. Thus, it appears that the proposed structural pattern hypothesis has received substantial support through experimental verification.

The advantages of mosquito biocontrol by stocking edible fish in rice paddies

Edible fish stocked in rice fields at a density of 600-800 fry per mu (1 mu = 1/15 hectare) for 150-170 days may act as an effective mosquito biocontrol agent. Common carp (Cyprinus carpio), grass carp Ctenopharyngodon idella) and Tilopia spp. killed late stage larvae and pupae of Anopheles sinensis and Culex tritaeniorrhyncus in laboratory and field trials. Stocking of fish in experimental rice fields decreased larval numbers significantly in comparison with control areas. Expansion of fish stocking in rice fields on a large scale over several years correlated with a marked decrease in malaria transmission. The addition of fish to the rice fields also resulted in increased yields. A ditch-ridge system of field arrangements is described for optimization of fish handling. Preliminary cost-benefit analysis indicates that this approach to mosquito control conveys considerable economic advantage and thus provides incentive to the community to participate in vector control programs. Farmers' experience in Guangxi over a number of years indicates that the use of edible fish for this purpose can be carried on a large, commercially viable scale.