Bifunctional 3D POM-based coordination polymers for improved pseudocapacitance and catalytic oxidation performance.

Developing novel high-efficiency supercapacitors as energy storage devices to solve the energy crisis is of vital significance. Meanwhile, designing highly active and selective oxidation catalysts for various sulfides is desirable but still a big challenge. To work out these problems, three novel 3D POM-based coordination polymers (POMCPs), formulated as [{Ag6(pytz)4}{SiMo12O40}] (1), [{Cu3(pytz)4}{SiMo12O40}]·5.5H2O (2) and [{Cu6(pytz)6}{SiMo12O40}]·2H2O (3) (pytz = 4-(5-(4-pyridyl)-1H-tetrazole)), are successfully prepared via a one-step synthetic strategy by changing different temperatures under hydrothermal or solvothermal conditions. In compounds 1 and 2, {SiMo12}, as 9-capped and 2-capped polyoxoanions, are engaged among the 2D Ag/Cu-organic sheets to generate the novel 3D POM-based coordination polymers. In addition, 1D Cu-organic chains are combined with 3-capped {SiMo12} polyoxoanions to construct 2D POM-based coordination polymers in 3. To our delight, as electrode materials for supercapacitors, the three compounds exhibit excellent specific capacitances of 261.76 F g-1, 248.82 F g-1 and 156.47 F g-1 at 0.5 A g-1, respectively. Besides, they can effectively and selectively catalyze the oxidation of various sulfides to sulfoxides.

FAT2 mutation is associated with better prognosis and responsiveness to immunotherapy in uterine corpus endometrial carcinoma.

BACKGROUND: Uterine corpus endometrial carcinoma (UCEC) ranks sixth among malignant tumors in women and the mortality is still rising. FAT2 gene has been considered to be related to the survival and prognosis of some certain diseases in previous studies, but the FAT2 mutation status in UCEC and its prognostic value has been rarely studied. Hence, the purpose of our study was to explore the role of FAT2 mutations for predicting prognosis and responsiveness to immunotherapy in patients with UCEC. METHODS: UCEC samples from the Cancer Genome Atlas database were analyzed. We evaluated the impact of FAT2 gene mutation status and clinicopathological characteristics on the prognosis of UCEC patients and used univariate and multivariate Cox analysis risk scores to independently predict patient overall survival (OS). Tumor mutation burden (TMB) values of the FAT2 mutant and non-mutant groups were computed by Wilcoxon rank sum test. The correlation of FAT2 mutation and half maximal inhibitory concentration (IC50) values of various anticancer drugs was analyzed. Gene Ontology data and Gene Set Enrichment Analysis (GSEA) were employed to examine the differential expression of genes between the two groups. Finally, a single-sample GSEA arithmetic was utilized to measure the abundance of tumor-infiltrating immune cells in UCEC patients. RESULTS: FAT2 mutations suggested better OS (p < 0.001) and disease-free survival (DFS) (p = 0.007) in UCEC. The IC50 values of 18 anticancer drugs were upregulated in FAT2 mutation patients (p < 0.05). The TMB and microsatellite instability values of patients with FAT2 mutations were significantly higher (p < 0.001). Next, the Kyoto Encyclopedia of Genes and Genomes functional analysis and GSEA revealed the potential mechanism of FAT2 mutation on the tumorigenesis and progression of UCEC. In addition, in reference to the UCEC microenvironment, the infiltration levels of activated CD4/CD8 T cells (p < 0.001/p = 0.001) and plasmacytoid dendritic cells (p = 0.006) were upregulated in the non-FAT2 mutation group, and Type 2 T helper cells (p = 0.001) were downregulated in the FAT2 mutation group. CONCLUSIONS: UCEC patients with FAT2 mutations have better prognosis and are more likely to respond to immunotherapy. FAT2 mutation may be a valuable predictor for prognosis and responsiveness to immunotherapy in UCEC patients.

Physiological and transcriptome analyses reveal the photosynthetic response to drought stress in drought-sensitive (Fengjiao) and drought-tolerant (Hanjiao) Zanthoxylum bungeanum cultivars.

As an important economical plant, Zanthoxylum bungeanum is widely cultivated in arid and semi-arid areas. The studies associated with photosynthesis under drought stress were widely carried out, but not yet in Z. bungeanum. Here, the photosynthesis of two Z. bungeanum cultivars (FJ, Z. bungeanum cv. "Fengjiao"; HJ, Z. bungeanum cv. "Hanjiao") was analyzed under drought stress using physiological indicators and transcriptome data. Drought decreased stomatal aperture and stomatal conductance (Gsw), reduced transpiration rate (E) and sub-stomatal CO2 concentration (Ci), and lowered chlorophyll and carotenoid content, which reduced the net photosynthetic rate (Pn) of Z. bungeanum. The higher photosynthetic rate in HJ stemmed from its higher chlorophyll content, larger stomatal aperture and Gsw, and higher Ci. Weighted gene co-expression network analysis (WGCNA) identified several ABA signal transduction genes (PYL4, PYL9, and PYR1), LCH-encoding genes (LHCB4.3), and chlorophyll metabolism genes (CRD1, PORA, and CHLH). Additionally, seven transcription factor genes were identified as important factors regulating photosynthesis under drought conditions. In general, a photosynthetic response model under drought stress was built firstly in Z. bungeanum, and the key genes involved in photosynthesis under drought stress were identified. Therefore, the results in our research provide important information for photosynthesis under drought and provided key clues for future molecular breeding in Z. bungeanum.

UPLC-MS/MS Profile Combined With RNA-Seq Reveals the Amino Acid Metabolism in Zanthoxylum bungeanum Leaves Under Drought Stress.

Zanthoxylum bungeanum leaves have a unique taste and incomparable nutritional value and hence are popular as a food item and traditional medicine in China. However, the studies on the metabolites in Z. bungeanum leaves are quite limited, especially for amino acids. Therefore, this study explored the amino acid component in Z. bungeanum leaves and also the accumulation mechanism under drought stress in two Z. bungeanum cultivars using the widely targeted metabolome combined with transcriptome analysis. A total of 56 amino acids and their derivatives were identified in Z. bungeanum leaves, including eight essential amino acids. The total amino acid content with most individual amino acids increased under progressive drought stress. More differentially accumulated amino acids (DAAs) and differentially expressed genes (DEGs) were found in FJ (Z. bungeanum cv. 'Fengjiao') than in HJ (Z. bungeanum cv. 'Hanjiao'). The orthogonal projections to latent structures discriminant analysis identified nine and seven indicator DAAs in FJ and HJ leaves, respectively. The weighted gene co-expression network analysis (WGCNA) showed that the green module was significantly correlated with most indicator DAAs and revealed the important role of FBA3, DELTA-OAT, PROC, and 15 transcription factor genes in regulating the amino acid synthesis. Furthermore, the correlation analysis and redundancy analysis (RDA) identified four candidate synthesis genes (ASNS, AK, ASPS, and PK) in amino acid biosynthesis pathway. This study provided useful information for the development of Z. bungeanum leaves in food and nutrition industry and also laid the foundations for future molecular breeding.

Intestinal metastasis from choriocarcinoma: a case series and literature review.

BACKGROUND: Gestational choriocarcinoma is a rare trophoblastic tumor that spreads mainly to the lung, liver, and central nervous system. Fewer than 5% of patients present with metastasis to the gastrointestinal system and have a poor prognosis CASE PRESENTATION: We describe four cases of patients with intestinal metastasis from choriocarcinoma who visited the First Affiliated Hospital of Zhejiang University School of Medicine and the First People's Hospital of Hangzhou between April 2012 and October 2019. Four patients presented with gastrointestinal symptoms or developed gastrointestinal symptoms during treatment for choriocarcinoma. Three patients had these intestinal lesions surgically removed, and the postoperative pathology results suggested choriocarcinoma. All patients received multiple chemotherapy regimens during treatment for suboptimal human chorionic gonadotropin (hCG) levels; one patient died 22 months after a definitive diagnosis was made, and the other three patients are still undergoing regular follow-up. CONCLUSION: Given the low incidence of intestinal metastases from choriocarcinoma, the metastatic route of intestinal metastases from choriocarcinoma remains to be elucidated, and diagnosis mainly depends on pathology findings. An effective treatment has not been determined, and surgical excision with chemotherapy is generally accepted.

NHC-Catalyzed Transformation Reactions of Imines: Electrophilic versus Nucleophilic Attack.

It is generally accepted that N-heterocyclic carbene (NHC)-catalyzed imine transformations are initiated by a nucleophilic attack (NA) by NHC. However, due to significant nucleophilicity of the iminyl nitrogen atom in imines, the electrophilic attack (EA) by electrophiles onto imine would also be a possible mechanism of these kinds of reactions. Therefore, we use the quantum mechanical approach to disclose that both the NA and EA modes could be switchable for a wide range of NHC-catalyzed transformations of imines.

Role of Emergency Surgery for Fatal Complications of Gestational Trophoblastic Neoplasia: A Single-Center Experience.

PURPOSE: High-risk gestational trophoblastic neoplasia (GTN) can lead to fatal complications; however, few reports have assessed emergency surgery as a treatment option for such complications. Thus, this study aimed to analyze the clinical features and prognosis of patients with GTN who underwent emergency surgery. PATIENTS AND METHODS: Thirteen patients with high-risk or ultra-high-risk GTN who underwent emergency surgery for fatal complications in the First Affiliated Hospital of Zhejiang University, School of Medicine from 2013 to 2020 were analyzed, and their medical records were reviewed. The patients' characteristics and treatment were evaluated with respect to outcomes. RESULTS: Thirteen patients with GTN who underwent 15 emergency surgical procedures were identified in our center. The mean International Federation of Gynecology and Obstetrics score of these patients was 14.8 (range, 11-19). Of the 13 patients, six underwent brain surgeries, such as tumor resection (n = 5) and conservative surgery (n = 1). All the patients received multi-agent chemotherapy after emergency surgery, and the mean time from emergency surgery to subsequent chemotherapy was 12.7 days. Of the 13 patients, 10 (77%) were cured and disease-free, with a follow-up period ranging from 3 months to 8 years. All the patients (n = 6) who underwent emergency brain surgery survived and achieved complete remission. CONCLUSION: For patients with high-risk GTN with fatal complications, especially brain lesions, emergency surgery combined with subsequent chemotherapy may provide a favorable prognosis.

Torrefaction of walnut oil processing wastes by superheated steam: Effects on products characteristics.

Walnut oil production waste (WOPW) is a by-product of walnut oil processing. The organic waste is rich in holocellulose and lignin, showing good potential to be converted by thermal process to valuable products. Superheated steam (SHS) torrefaction is a recently proposed thermal process enabling fast and unformal biomass heating, resulting in high-quality solid products as direct fuel. The potential of SHS to torrefy lipids and proteins (being rich in WOPW) is attractive for broader application of SHS torrefaction to upgrade more biomass wastes. SHS torrefaction was studied in this work to upgrade WOPW for solid products with different reaction temperatures (200, 250, 300 °C) and residence times (20, 40, 60 min). The lowest weight yield was 43.64 wt% under the severest treatment of 300 °C and 60 min, accompanied with the highest energy enhancement of 1.34 (reaching HHV of 27.03 MJ/kg). Response surface method is employed to reveal the effects of temperature and residence time. Residence time of 40 min under 300 °C was supposed to be an ideal condition to upgrade WOPW with HHV of 26.68 MJ/kg and in the range of coal from Van Krevelen diagram. Combustion indices (e.g., fuel ratio, combustion index, and volatile ignitability) indicated that the aforementioned torrefied WOPW had favourable properties as co-firing material. On the other hand, combustion behaviours analysis demonstrated that SHS torrefied WOPW could perform well as direct fuel. Aqueous effluent was also condensed and analyzed, where products from lipids and proteins were massively presented, giving an insight into the decomposition of those two constitutes undergoing SHS torrefaction.

[The physiology of plant seed aging: a review].

Seed quality plays an important role in the agricultural and animal husbandry production, the effective utilization of genetic resources, the conservation of biodiversity and the restoration and reconstruction of plant communities. Seed aging is a common physiological phenomenon during storage. It is a natural irreversible process that occurs and develops along with the extension of seed storage time. It is not only related to the growth, yield and quality of seed and seedling establishment, but also has an important effect on the conservation, utilization and development of plant germplasm resources. The physiological mechanisms of seed aging are complex and diverse. Most studies focus on conventional physiological characterization, while systematic and comprehensive in-depth studies are lacking. Here we review the recent advances in understanding the physiology of seed aging process, including the methods of seed aging, the effect of aging on seed germination, and the physiological and molecular mechanisms of seed aging. The change of multiple physiological parameters, including seed vigor, electrical conductivity, malondialdehyde content and storage material in the seed, antioxidant enzyme activity and mitochondrial structure, were summarized. Moreover, insights into the mechanism of seed aging from the aspects of transcriptome, proteome and aging related gene function were summarized. This study may facilitate the research of seed biology and the conservation and utilization of germplasm resources.

Fuel properties and combustion behaviors of fast torrefied pinewood in a heavily loaded fixed-bed reactor by superheated steam.

Superheated steam (SHS) was capable of fast and uniformly torrefying heavily loaded biomass. This work detailedly investigated the torrefied biomass in terms of fuel property and combustion behavior. The reactor chamber (300 ml) was fully loaded with pinewood pellets (160 g). Overall residence times were 20, 40 and 60 min (including preheating and holding periods) under 225, 275 and 325 °C. Biomass was estimated by elements, TG, FTIR, HHV, fuel property, combustion and pyrolysis behaviors, combustion kinetics and moisture reabsorption. Holding period as short as 2 min at 325 °C with a heating rate of 15 °C‧min-1 was found to enhance energy density by 45% and generated homogeneous coal-like products with HHV of 26.76 MJ‧kg-1. Fixed carbon content increased to 64.84 wt%. The combustion activation energy increased to 79.66 kJ‧mol-1. Combustion indices and behaviors indicated that torrefied biomass had benign characteristics either for co-firing or as fuel. All suggests good potential of SHS torrefaction to obtain fuel alternatives.

PADI6 Regulates Trophoblast Cell Migration-Invasion Through the Hippo/YAP1 Pathway in Hydatidiform Moles.

PURPOSE: Peptidyl arginine deiminase, type VI (PADI6), a member of the subcortical maternal complex, plays an important role in oocyte growth and the development of fertilized oocytes. Human patients with PADI6 mutations can suffer from multiple reproductive deficiencies including hydatidiform moles and miscarriages. Recent studies have demonstrated that the Hippo signaling pathway plays a central role in the specification of the first cell fates and the maintenance of the human placental trophoblast epithelium. The present study aimed to verify the hypothesis that PADI6 regulates the biological functions of trophoblast cells by targeting YAP1 and to explore the mechanism by which PADI6 accomplishes this in trophoblast cells. METHODS: Villi from HMs and human trophoblast cell lines were used to identify the localization of PADI6 and YAP1 by immunohistochemistry and immunocytochemistry. PADI6 overexpression and knockdown were induced in human trophoblast cells. Co-immunoprecipitation was used to explore the interaction between PADI6 and YAP1. Wound healing, Transwell and EdU staining assays were used to detect migration, invasion and proliferation. Flow cytometric analysis was used to analyze the cell cycle and apoptosis. ß-Tubulin and F-actin levels were determined by Western blot, quantitative real-time PCR and phalloidin staining. RESULTS: The results showed that PADI6 and YAP1 had the same expression pattern in villi and colocalized in the cytotrophoblast. An interaction between PADI6 and YAP1 was also confirmed in human trophoblast cell lines. We found that PADI6 positively regulated the expression of YAP1. Functionally, overexpression of PADI6 promoted cell cycle progression and enhanced migration, invasion, proliferation and apoptosis, whereas downregulation of PADI6 showed the opposite effects. CONCLUSION: This study demonstrates that YAP1 is a novel target of PADI6 that serves as an important regulator of trophoblast dysfunction. The crosstalk between the Hippo/YAP1 pathway and the SCMC might be a new topic to explore to uncover the pathological mechanisms of HMs.

MST4 Regulates Epithelial-Mesenchymal Transition of Choriocarcinoma by Mediating TGF-ß1 Expression.

BACKGROUND: Mammalian Ste20-like kinase 4 (MST4), also known as serine/threonine kinase 26 (STK26), promotes development of several cancers and is found to be highly expressed in the placenta. However, in choriocarcinoma that originated from the placenta, the expression of MST4 was undetermined and its mechanism was unknown. In this study, the expression of MST4 in choriocarcinoma as well as the underlying mechanism was explored. PURPOSE: To detect the expression of MST4 in patient samples and mechanism of mediating EMT by MST4 in choriocarcinoma. PATIENTS AND METHODS: The metastatic lesions of choriocarcinoma (n=17) and volunteer villus (n=17) were collected to determine MST4 expression using immunohistochemistry and H&E staining. We use siRNA and lentiviral vector to knockdown MST4 and use plasmid to overexpress MST4 in choriocarcinoma. Then, we apply real-time polymerase chain reaction (RT-PCR), Western blot assay and immunofluorescence assay to detect target protein expressions. Cell invasion and migration and cell proliferation were detected by transwell assay and wound healing assay and CCK-8 and cell colony formation. RESULTS: MST4 is lowly expressed in the metastatic lesions of choriocarcinoma patients when compared with normal villus. Knockdown of MST4 activated epithelial-mesenchymal transition (EMT) process, significantly increasing the ability of invasion and migration in choriocarcinoma cell lines (JAR and JEG-3). In contrast, the EMT process was restrained in choriocarcinoma cell lines with overexpressed MST4. Meanwhile, genome-wide gene expression array, Western blot and ELISA revealed that tumor growth factor-beta 1 (TGF-ß1) has significantly increased. The EMT process and metastatic prompting biofunction were reversed after using TGF-ß1 inhibitor (LY364947) in the choriocarcinoma cell lines with MST4 knockdown. CONCLUSION: Our studies demonstrated that MST4 was lowly expressed in patient samples. Additionally, JAR and JEG-3 increase cell invasion and migration ability while there is no influence on cell proliferation with MST4 knockdown. Conversely, the metastatic ability of JAR and JEG-3 was decreased with overexpressed MST4. Moreover, TGF-ß1 was a key factor after MST4 knockdown. In conclusion, MST4 affects choriocarcinoma EMT by mediating TGF-ß1 expression.

Tendon stem cell-derived exosomes regulate inflammation and promote the high-quality healing of injured tendon.

BACKGROUND: Tendon stem cells (TSCs) have been reported to hold promises for tendon repair and regeneration. However, less is known about the effects of exosomes derived from TSCs. Therefore, we aimed to clarify the healing effects of TSC-derived exosomes (TSC-Exos) on tendon injury. METHODS: The Achilles tendons of Sprague-Dawley male rats were used for primary culture of TSCs and tenocytes, and exosomes were isolated from TSCs. The proliferation of tenocytes induced by TSC-Exos was analyzed using an EdU assay; cell migration was measured by cell scratch and transwell assays. We used western blot to analyze the role of the PI3K/AKT and MAPK/ERK1/2 signaling pathways. In vivo, Achilles tendon injury models were created in Sprague-Dawley rats. Rats (n = 54) were then randomly assigned to three groups: the TSC-Exos group, the GelMA group, and the control group. We used immunofluorescence to detect changes in the expression of inflammatory and apoptotic markers at 1 week after surgery. Histology and changes in expression of extracellular matrix (ECM)-related indices were assessed by hematoxylin-eosin (H&E) staining and immunohistochemistry at 2 and 8 weeks. The collagen fiber diameter of the healing tendon was analyzed at 8 weeks by transmission electron microscopy (TEM). RESULTS: TSC-Exos were taken up by tenocytes, which promoted the proliferation and migration of cells in a dose-dependent manner; this process may depend on the activation of the PI3K/AKT and MAPK/ERK1/2 signaling pathways. At 1 week after surgery, we found that inflammation and apoptosis were significantly suppressed by TSC-Exos. At 2 and 8 weeks, tendons treated with TSC-Exos showed more continuous and regular arrangement in contrast to disorganized tendons in the GelMA and control groups, and TSC-Exos may help regulate ECM balance and inhibited scar formation. Further, at 8 weeks, the TSC-Exos group had a larger diameter of collagen compared to the control group. CONCLUSIONS: Our data suggest that TSC-Exos could promote high-quality healing of injured tendon, which may be a promising therapeutic approach for tendon injury.

Can ovaries be preserved after an ovarian arteriovenous disconnection? One case report and a review of surgical treatment using Da Vinci robots for aggressive ovarian fibromatosis.

BACKGROUND: The ovary is an important organ of the female reproductive system, which produces oocytes and secretes reproductive hormones. Ovaries have complex dual blood supplies with their blood supply being the core component to protect and ensure ovarian function. Ovarian preservation surgery often encounters problems related to whether or not to preserve ovarian vessels on the affected side. CASE PRESENTATION: This study reports on the case of a 30-year-old female patient with the retroperitoneal fibromatosis that had a history of uterine leiomyoma. During the operation, the ovarian arteries and veins were separated according to what was found during the procedure. A postoperative examination demonstrated good function and morphology of the ovary. CONCLUSIONS: A thorough review of academic journals combined with our collection of clinical data was conducted, which confirmed the double blood supply source to the ovaries. As a result of this exploration, a new surgical method is being proposed that is designed to protect the ovaries. By conducting this new procedure, the patient's disease was not only halted and ultimately cured, but results demonstrate that the method was also able to retain the shape and function of the ovary. The postoperative satisfaction of the patient was significantly improved.

The Studies on Structure and Stability of CaBn Clusters.

Calcium-boron systems have excellent properties of hardness, strength, and chemical stability, and we studied a series of CaBn clusters to investigate their structures and relative stability. The results showed the most stable structures of CaBn clusters are not planar. The B atoms tend to get together and form the planar ring to stabilize the structure, and the Ca atoms are coordinated to the periphery of the formations. The average binding energy (Eb), fragmentation energy (EF), second-order energy difference (Δ2E), adiabatic detachment energy (ADE), and adiabatic electron affinity (AEA) of the CaBn clusters were calculated to investigate the relative stability and the ability of removing or obtaining an electron. As shown by the results, EF and Δ2E values had obvious odd-even alteration as n increased, which indicated that the formations CaB4, CaB6, and CaB8 were more stable. The ADE values for CaBn clusters with even values of n were higher than those with odd values of n, which indicated CaBn clusters with even values of n had difficultly removing an electron. The AEA values of CaB3 and CaB7 were larger than the others, which meant CaB3 and CaB7 easily obtained an electron. These results provide a useful reference for understanding the formation mechanism and stability of the alkaline earth metal boride as well as guidance for synthesizing the CaBn clusters.

Hepatocyte growth factor plays a dual role in tendon-derived stem cell proliferation, migration, and differentiation.

Heterotopic ossification is common in tendon healing after trauma, but the detailed mechanisms remain unknown. Tendon-derived stem cells (TDSCs) are a type of progenitor cell found in the tendon niche, and their incorrect differentiation after trauma may lead to tendon calcification. The expression of hepatocyte growth factor (HGF) presents drastic fluctuations in serum/tissue after trauma and was found to activate quiescent stellate cells and contribute to wound healing; however, its potential role in TDSCs remains elusive. In this study, TDSCs isolated from rats were cultured in media containing HGF with or without a signaling inhibitor, and the proliferation, migration, and differentiation ability of TDSCs were measured to determine the role and mechanism of HGF in TDSCs. We showed that HGF promotes TDSC proliferation and migration but inhibits TDSC osteogenic differentiation ability. HGF activated-HGF/c-Met, mitogen-activated protein kinase (MAPK)/extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling, which was positively correlated with TDSCs proliferation and migration but negatively related to TDSC osteogenic differentiation ability. The phosphorylation of Smad1/5/8 was also negatively related to HGF/c-Met, MAPK/ERK1/2, and PI3K/AKT signaling, which demonstrated that the inhibition of osteogenic differentiation was dependent on BMP/Smad1/5/8 signaling. Overall, we showed that HGF could promote TDSCs proliferation and migration and inhibit osteogenic differentiation in vitro, suggesting a potential role for HGF as a cytokine treatment of tendon trauma.

The cisplatin-induced lncRNA PANDAR dictates the chemoresistance of ovarian cancer via regulating SFRS2-mediated p53 phosphorylation.

As a component of p53-dependent lncRNA (long non-coding RNA), PANDAR (the promoter of CDKN1A antisense DNA damage activated RNA) participates in the epigenetic regulation in human cancer. However, the involvement of PANDAR in cancer chemoresistance is unknown. In this study, we report that PANDAR serves as a negative regulator of cisplatin sensitivity in human ovarian cancer via PANDAR-SRFS2-p53 feedback regulation in nuclear. Our data showed that among the drugs commonly used in ovarian cancer therapy, cisplatin induces higher levels of PANDAR compared with doxorubicin and paclitaxel. We also proved that PANDAR exhibited higher expression in cisplatin-resistant ovarian cancer tissues and cells, compared with cisplatin-sensitive ones, and this expression pattern depends on wild-type p53 (wt-p53), not mutant-p53 (mt-p53). In vitro and in vivo, PANDAR overexpression improved cell survival rate and tumor growth in response to cisplatin, while depletion of PANDAR leads to a reduced tumor growth. Further investigation revealed that PANDAR-reduced cisplatin sensitivity was likely or partly due to the PANDAR-binding protein SFRS2 (arginine/serine-rich 2), a splicing factor with the ability to negative regulate p53 and its phosphorylation at Serine 15 (Ser15). This feedback regulation of PANDAR-SFRS2-p53 leads to a reduced transactivation of p53-related pro-apoptotic genes, such as PUMA (p53-upregulated modulator of apoptosis). In addition, in platinum-treated patients with relapsed ovarian cancer, resistant period was positively correlated with the expression of PANDAR and SFRS2, and inversely associated with expression of p53-Ser15 and PUMA in these clinical tissues. Last but not least, the role of PANDAR in chemoresistance was confirmed in patients with ovarian cancer. These findings reveal a novel regulatory maneuver of cancer cells in response to chemostress, and might shed light on overcoming cisplatin resistance in ovarian cancer.

Insights into Ag(i)-catalyzed addition reactions of amino alcohols to electron-deficient olefins: competing mechanisms, role of catalyst, and origin of chemoselectivity.

The competing mechanisms of Ag(i)-catalyzed chemoselective addition reactions of amino alcohols and electron-deficient olefins leading to the O-adduct or N-adduct products were systematically studied with density functional theory methods. Calculations indicate that the AgHMDS/dppe versus AgOAc/dppe catalytic systems can play different roles and thereby generate two different products. The AgHMDS/dppe system works as a Brønsted base to deprotonate the amino alcohol OH to form the Ag-O bond, which leads to formation of the O-adduct. In contrast, the AgOAc/dppe system mainly acts as a Lewis acid to coordinate with O and N atoms of the amino alcohol, but it cannot act as the Brønsted base to further activate the OH group because of its weaker basicity. Therefore, the AgOAc/dppe catalyzed reaction has a mechanism that is similar to the non-catalyzed reaction, and generates the same N-adduct. The obtained insights will be important for rational design of the various kinds of cooperatively catalyzed chemoselective addition reactions, including the use of the less nucleophilic hydroxyl groups of unprotected amino alcohols.

Density functional theory study on structure and stability of BeBn+ clusters.

RATIONALE: Boride compounds hold promise for broad applications in the field of optoelectronics due to their high-temperature resistant, corrosion resistant and antioxidant properties. In order to reveal the formation mechanism of alkali and alkaline earth metal doped boron clusters, theoretical studies of these systems are required. METHODS: All the possible geometrical structures of BeBn+ clusters (n = 1-8) were optimized at the B3LYP/6-311+G(d) level; the harmonic vibration frequencies were obtained to examine the true stability and give the zero-point vibration energy at that theoretical level. The single point energies of all the structures were computed at the CCSD(T)/aug-cc-pVDZ level. For the most stable structures, the average binding energy (Eb ), the fragmentation energy (EF ) and second-order difference of total energy (Δ2 E) were used to evaluate the relative stability of clusters. RESULTS: Most of the BeBn+ clusters are planar in structure; the B atoms tend to aggregate to form a boron ring, and the coordinating Be atoms are on the periphery of the clusters. The fragmentation energy and second-order difference of total energy show that there is an obvious odd-even alteration as n increases, and local-maxima when n is odd. CONCLUSIONS: A systematic theoretical investigation on the geometries, stabilities and electronic properties of BeBn+ clusters has been carried out where n = 1-8. The results provide a useful reference for understanding the formation mechanism and stability of these clusters, as well as guidance for finding larger size clusters.

Effects of the donor age on proliferation, senescence and osteogenic capacity of human urine-derived stem cells.

To study the effects of the donor age on the application potential of human urine-derived stem cells (hUSCs) in bone tissue engineering, by comparing proliferation, senescence and osteogenic differentiation of hUSCs originated from volunteers with different ages. The urine samples were collected from 19 healthy volunteers (6 cases from children group aged from 5 to 14, 5 cases from middle-aged group aged from 30 to 40, and 8 cases from the elder group aged from 65 to 75), and hUSCs were isolated and cultured. The cell morphology was observed by microscope and the cell surface markers were identified by flow cytometry. Their abilities to undergo osteogenic, adipogenic and chondrogenic differentiation were determined in vitro, and cell proliferation analyses were performed using Cell Counting Kit-8 (CCK8) Assay. The senescence of hUSCs among three groups was assessed by senescence-associated ß galactosidase staining. After osteogenic differentiation, the alkaline phosphatase (ALP) activity of hUSCs was measured and expression of osteogenic-related runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. The hUSCs isolated from urine samples were adherent cells displayed "rice gain"-like and "spindle-shaped" morphology, expressing surface markers of mesenchymal stem cells (MSCs) (CD73, CD90, CD105) and the peripheral cell marker (CD146), but not hematopoietic stem cell markers (CD34, CD45) or the embryonic stem cell marker (OCT3/4). The obtained hUSCs could be induced into osteogenic, adipogenic or chondrogenic differentiation. The hUSCs from the children group showed higher proliferation and lower tendency to senescence than those from the middle-aged and elder groups. After osteogenic induction, the ALP activity and RUNX2 and OCN expression of hUSCs from the children group were higher than those from the elder group. While no significant differences were observed when comparing the middle-aged group with the children group or the elder group. Donor age could influence the potency of hUSCs on proliferation, senescence and capacity of osteogenic differentiation. hUSCs from children group have shown higher proliferation, lower tendency to senescence, and stronger osteogenic capacity, which means to be more suitable for basic research and have better clinical application. Furthermore, hUSCs from all groups suggest the application potential in bone tissue engineering as seed cells.