Search

The present study aimed to isolate and characterize side population (SP) cells in the human lung cancer A549 cell line, and elucidate the molecular mechanism of SP cells underlying lung cancer. The SP and non-SP (NSP) cells in A549 cells were isolated and their differentiation was analyzed by fluorescence-activated cell sorting. An in vitro plate clone assay, Matrigel® Transwell assay and chemoresistance analysis of the sorted SP and NSP cells were performed. In addition, the sorted SP and NSP cells were injected into BALB/c nude mice to detect their tumorigenic potential in vivo. The expression of ATP-binding cassette sub-family G member 2 (ABCG2) in transplanted tumors was detected by immunohistochemistry. The SP and NSP cells were successfully isolated. The results demonstrated that SP cells accounted for 1.09% of live A549 cells. SP cells produced SP and NSP cells, while NSP cells only produced NSP cells. In addition, SP cells formed more colonies, exhibited improved invasive ability and increased levels of chemoresistance compared with NSP cells in vitro. SP cells demonstrated a higher tumorigenic potential in BALB/c nude mice, and the number of ABCG2-positive cells in the SP xenograft tumors were significantly increased compared with that in the NSP xenograft tumors. The present study indicated that SP cells isolated from the human lung cancer A549 cell line demonstrated increased tumorigenicity, and improved invasive ability and chemoresistance compared with NSP cells. In addition, detection of ABCG2 expression may assist in predicting the chemotherapeutic outcome of patients, and serve as a target for treating lung cancer.

As a generalization of the class of inverse semigroups, the class of Ehresmann semigroups is introduced by Lawson and investigated by many authors extensively in the literature. In particular, Gomes and Gould construct a fundamental Ehresmann semigroup CE from a semilattice E which plays for Ehresmann semigroups the role that TE plays for inverse semigroups, where TE is the Munn semigroup of a semilattice E. From a varietal perspective, Ehresmann semigroups are derived from reduction of inverse semigroups. In this paper, from varietal perspective Ehresmann semigroups are extended to generalized Ehresmann semigroups derived instead from normal orthodox semigroups (i.e. regular semigroups whose idempotents form normal bands) with an inverse transversal. We present here a semigroup C(I,Λ,E∘) from an admissible triple (I, Λ, E∘) that plays for generalized Ehresmann semigroups the role that CE from a semilattice E plays for Ehresmann semigroups. More precisely, we show that a semigroup is a fundamental generalized Ehresmann semigroup whose admissible triple is isomorphic to (I, Λ, E∘) if and only if it is (2,1,1,1)-isomorphic to a quasi-full (2,1,1,1)-subalgebra of C(I,Λ,E∘). Our results generalize and enrich some results of Fountain, Gomes and Gould on weakly E-hedges semigroups and Ehresmann semigroups.

As generalizations of inverse semigroups, restriction semigroups and regular $$*$$ -semigroups are investigated by many authors extensively in the literature. In particular, Lawson and Hollings have proved that the category of restriction semigroups together with prehomomorphisms (resp. (2,1,1)-homomorphisms) is isomorphic to the category of inductive categories together with ordered functors (resp. strongly ordered functors), which generalizes the well-known Ehresmann–Schein–Nambooripad theorem (ESN theorem for short) for inverse semigroups. On the other hand, Imaoka and Fujiwara have also obtained an ESN-type theorem for locally inverse regular $$*$$ -semigroups. Recently, Jones generalized restriction semigroups and regular $$*$$ -semigroups to P-restriction semigroups from a varietal perspective and considered the constructions of P-restriction semigroups by using Munn’s approach. In this paper, we shall study the class of P-restriction semigroups by using “category approach.” We introduce the notion of inductive generalized categories over local semilattices by which a class of P-restriction semigroups called locally restriction P-restriction semigroups is described. Moreover, we show that the category of locally restriction P-restriction semigroups together with (2,1,1)-prehomomorphisms (resp. (2,1,1)-homomorphisms) is isomorphic to the category of inductive generalized categories over local semilattices together with preadmissible mappings (resp. admissible mappings). Our work may be regarded as extending the ESN-type theorems for restriction semigroups and locally inverse regular $$*$$ -semigroups, respectively.

Osteosarcoma is the most common bone tumor affecting both adolescents and children. Early detection is critical for the effective treatment of the disease. Derived from cancer cells, miR‑21 contained within exosomes in the tumor microenvironment may act on both cancer cells and the surrounding tumor microenvironment (TME), including immune cells, endothelial cells and fibroblasts. In human serum and plasm, the level of exosomal miR‑21 between osteosarcoma patients and healthy controls differs, supporting the role of miR‑21 as a biomarker for osteosarcoma. The involvement of a number of miR‑21 target genes in tumor progression suggests that miR‑21 may significantly affect the plasticity of cancer cells, leading to tumor progression, metastasis, angiogenesis and immune escape in osteosarcoma. Understanding the biogenesis and functions of exosomal miR‑21 is of great value for the diagnosis and therapy of cancer, including osteosarcoma. The present review discusses the role of miR‑21 in the tumor microenvironment, and in the development and progression of osteosarcoma, with an aim to summarize the functions of this miRNA in cancer.

Rush hour network capacity enhancement is one of the most hard-to-solve problems in the field of network optimization. With the bust of data traffic requirement in cellular communication, 5G network will face this challenge in future. However, there is few effective solutions to this problem for 5G network optimization. In this paper, a novel solution based on hot spot floating prediction is proposed. Our solution consists of a traffic prediction method for hot spot floating trend estimation, and a semi-dynamic distributed unit (DU) and active antenna unit (AAU) mapping to fit the forecasted high traffic burst with proper DU-AAU mapping. The proposed solution could fit real network irregular gNB distribution. Simulation outcomes indicate that the hot spot floating prediction precision outperforms around 10% in normalized root mean squired error with the existing prediction methods, and our semi-dynamic DU-AAU mapping solution receives a 20% throughput gain on average compared with that without DU-AAU mapping network solution.

Variant rs7034162 in NFIB was reported to be associated with metastasis of osteosarcoma in European cases with genome-wide significance. Our purpose was to replicate the association of rs7034162 with the metastasis of osteosarcoma in the Chinese population and to further characterize the expression level of NFIB in osteosarcoma tissues. A total of 321 patients were included in this study. Variant rs7034162 was genotyped for each patient using the Taqman genotyping assay. Fifty-two cases of tumor tissues and adjacent normal tissues were collected during surgery. The χ2 test was used to investigate the association of rs7034162 with the metastasis of osteosarcoma. The Student t test was used to compare the gene expression between patients with metastasis and those without metastasis. The messenger RNA expression level of NFIB was then compared among different genotypes of rs7034162 with 1-way analysis of variance test. Ninety-three patients were found to have metastasis. Patients with genotype AA had remarkably higher incidence of metastasis than those with genotype TT (34.4% vs 17.1%, P = .002). Patients with metastasis were found to have significantly higher rate of allele A than those without metastasis (53.2% vs 43.9%, P = .03). The messenger RNA expression of NFIB was significantly lower in tumor tissues of patients with metastasis than in those without metastasis (0.00035 ± 0.00017 vs 0.00063 ± 0.0025, P < .001). Compared to patients with genotype TT, those with genotype AA had remarkably decreased expression of NFIB (0.00033 ± 0.0014 vs 0.00067 ± 0.00037, P = .01). Single-nucleotide polymorphism rs7034162 was associated with metastasis of osteosarcoma in the Chinese population possibly via downregulation of NFIB. Further network analyses revealing the related pathways can help elucidate the molecular mechanism of distant metastasis in patients with osteosarcoma.

A cobalt and copper catalyzed reaction protocol has been developed to achieve the oxidative C–H/N–H annulation of benzamides containing an 8-aminoquinoline moiety as the directing group with ketones. Structurally diverse isoindolin-1-ones were furnished by the reaction of various substituent benzamides with ketones.

The sleep quality of patients with osteosarcoma (OS) was poorly understood. We aimed to evaluate the prevalence of sleep dysfunction in adolescent patients with OS using the Pittsburgh Sleep Quality Index (PSQI) and to further investigate the psychometric properties of the PSQI in this cohort of patients. Fifty four adolescent patients with OS who underwent chemotherapy treatment in our clinic centre were included. Sleep quality was assessed with the Chinese PSQI. Cronbach's alpha was calculated to evaluate the internal consistency. The confirmatory factor analysis (CFA) was used to determine the fitness of a two-factor structure. Sleep disturbance was observed in 57.4% (31/54) of the patients. Patients with the presence of metastasis or more than 2 cycles of chemotherapy were found to have remarkably higher median global score. The overall Cronbach's alpha was 0.87. The CFA showed an overall comparative fit index of 0.97, a root mean square error of approximation of 0.06 and a standardised root mean square residual of 0.07 respectively. PSQI was a reliable instrument to evaluate the sleep quality of adolescent patients with OS. Over half of the patients may experience sleep disturbance during the treatment. Early psychological interventions were recommended to improve the sleep quality of the patients.

e23531 Background: Standard treatment for patients with unresectable locally advanced or metastatic soft-tissue sarcoma is chemotherapy based on anthracyclines, while the tolerance of chemotherapy is limited. We assessed if anlotinib, a multitarget tyrosine kinase inhibitor, is efficacy and safety for the first-line treatment of these patients. Methods: This is an open-label, single-arm, multicenter, phase II clinical trial (NCT03792542) including 44 planned subjects. Eligible patients were aged 18-70 years old, diagnosed with locally advanced or metastatic soft-tissue sarcoma and had at least one measurable lesion according to RECIST 1.1. Other inclusion criteria included ECOG PS 0̃2, chemotherapy and anti-angiogenesis treatment naïve. Patients were administrated 12mg anlotinib once daily for 14 days every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Safety assessment was done in patients who received at least one dose of anlotinib. Here we report the results of a planned interim analysis. Results: From April 2019 to December 2020, 29 patients (16 males and 13 females) were enrolled from 7 hospitals in China. The median age is 57 (range 23-69). Pathological types included liposarcoma (n = 8), undifferentiated pleomorphic sarcoma (n = 5), fibrosarcoma (n = 5), synovial sarcoma (n = 4), and others (n = 7). At the data cutoff date on December 31, 2020, the median duration of treatment was 5.3 months, and the median PFS was not reached. 26 patients were eligible for the evaluation of tumor response.1 achieved partial response (PR) and the objective response rate (ORR) was 3.85% (1/26). 24 had stale disease (SD) and the disease control rate (DCR) was 96.2% (25/26). The clinical benefit rate (CBR), defined as the proportion of patients who achieved durable disease control (CR/PR/SD) more than 4 and 6 months, were 65.4% (17/26) and 38.5% (10/26) respectively. Most adverse events (AE) were grade 1 or 2. The most common grade 3 AE was hypertension (17.2%). No grade 4 AEs or treatment related death occurred in this study through the last follow-up. Conclusions: This interim analysis showed anlotinib of promising efficacy and favorable tolerance in the first-line treatment of locally advanced or metastatic soft- tissue sarcoma. Clinical trial information: NCT03792542.

Photocatalytic degradation based on semiconductor is a potential technology for water pollution treatment by utilizing light irradiation. As a new p-type semiconductor material, CuBi2O4 is favored by researchers due to its excellent photocatalytic properties. Herein, a group of CuBi2O4 nanospheres were synthesized by simple hydrothermal method, in which the formation and transformation process of CuBi2O4 microsphere structure was studied by adjusting the hydrothermal reaction time. On this basis, a series Z-Scheme heterojunctions with different mass ratios of CuBi2O4/CdMoO4 nanocomposites were constructed and the formation mechanism of Z-scheme heterojunction was described detailedly. The results of the study confirmed that CuBi2O4/CdMoO4 (10 %) composites exhibited excellent photocatalytic activity, with a high degradation rate of 95.36 % for MB under visible light irradiation, by comparison with bare CuBi2O4 and CdMoO4. In order to improve the quantum efficiency, doping CdMoO4 onto CuBi2O4 greatly improved the surface charge migration rate of CuBi2O4 and reduced the rate of electron-hole pairs recombination. The degradation rate of CuBi2O4/CdMoO4 (10 %) remained over 85 % after three times cycling experiments, demonstrating that the heterojunction has good repeatability and stability. The free radical trapping experiments demonstrated that the h+ and O2– were the main substances involved in photocatalytic oxidation-reduction, which match the energy band, and was consistent with the mechanism of Z-Scheme heterojunctions. This study stated that establishment of a novel CuBi2O4/CdMoO4 heterojunction composite photocatalyst is a new ideal way to carry out environmental pollution treatment and clean energy.

A novel Ag/ CuBi2O4/ Ag2MoO4 composite was successfully prepared by ion exchange as well as reduction methods. The crystal structure, surface chemical composition and micromorphology characteristics of the samples were determined by a variety of testing methods and the optical properties of all synthesized catalysts were described in detail by PL, UV–Vis DRS and SPS. The ternary Ag/ CuBi2O4/ Ag2MoO4 composites were superior to other samples in visible light catalytic degradation of methylene blue (MB), it was mainly attributed to the interaction between CuBi2O4 and Ag2MoO4 and the SPR effect of Ag nanoparticles, which resulted in a significantly higher separation efficiency of photogenerated electrons and holes. Meanwhile, the degradation efficiency of MB was still maintained above 80% by three recycling experiments. Finally, a possible mechanism for photocatalytic degradation was proposed.

It is well known that Cayley graphs of groups are automatically vertex-transitive. A pioneer result of Kelarev and Praeger implies that Cayley graphs of semigroups can be regarded as a source of possibly new vertex-transitive graphs. In this note, we consider the following problem: Is every vertex-transitive Cayley graph of a semigroup isomorphic to a Cayley graph of a group? With the help of the results of Kelarev and Praeger, we show that the vertex-transitive, connected and undirected finite Cayley graphs of semigroups are isomorphic to Cayley graphs of groups, and all finite vertex-transitive Cayley graphs of inverse semigroups are isomorphic to Cayley graphs of groups. Furthermore, some related problems are proposed.

A pair of enantioselective switchable bifunctional catalysts are shown to promote a range of conjugate addition reactions in up to 95 : 5 e.r. and 95% conversion. Each catalyst can be switched OFF using conditions that switch the other catalyst ON. Catalyst ON : OFF ratios of up to 98 : 2 and 1 : 99 were achieved, with a ratio of reaction rates of up to 16 : 1 between the ON and OFF states, maintained over complete ON–OFF–ON and OFF–ON–OFF cycles. However, simultaneous operation of the catalyst pair in the same reaction vessel, which in principle could allow product handedness to be switched by simple E–Z isomerisation of the catalyst pair, was unsuccessful. In this first generation complementary pair of enantioselective switchable organocatalysts, the OFF state of one catalyst inhibits the ON state of the other.

Thiostrepton (TSR), an archetypal bimacrocyclic thiopeptide antibiotic that arises from complex posttranslational modifications of a genetically encoded precursor peptide, possesses a quinaldic acid (QA) moiety within the side-ring system of a thiopeptide-characteristic framework. Focusing on selective engineering of the QA moiety, i.e., by fluorination or methylation, we have recently designed and biosynthesized biologically more active TSR analogs. Using these analogs as chemical probes, we uncovered an unusual indirect mechanism of TSR-type thiopeptides, which are able to act against intracellular pathogens through host autophagy induction in addition to direct targeting of bacterial ribosome. Herein, we report the accumulation of 6'-fluoro-7', 8'-epoxy-TSR, a key intermediate in the preparation of the analog 6'-fluoro-TSR. This unexpected finding led to unveiling of the TSR maturation process, which involves an unusual dual activity of TsrI, an α/β-hydrolase fold protein, for cascade C-N bond cleavage and formation during side-ring system construction. These two functions of TsrI rely on the same catalytic triad, Ser72-His200-Asp191, which first mediates endopeptidyl hydrolysis that occurs selectively between the residues Met-1 and Ile1 for removal of the leader peptide and then triggers epoxide ring opening for closure of the QA-containing side-ring system in a regio- and stereo-specific manner. The former reaction likely requires the formation of an acyl-Ser72 enzyme intermediate; in contrast, the latter is independent of Ser72. Consequently, C-6' fluorination of QA lowers the reactivity of the epoxide intermediate and, thereby, allows the dissection of the TsrI-associated enzymatic process that proceeds rapidly and typically is difficult to be realized during TSR biosynthesis.

In this paper, we study battery capacity design for battery electric vehicles (BEVs). The core of such design problems is to find a good tradeoff between minimizing the capacity to reduce financial costs of drivers and increasing the capacity to satisfy daily travel demands. The major difficulty of such design problems lies in modeling the diversity of daily travel demands. Based on massive trip records of taxi drivers in Beijing, we find that the daily vehicle miles traveled (DVMT) of a driver (e.g., a taxi driver) may change significantly in different days. This investigation triggers us to propose a mixture distribution model to describe the diversity in DVMT for various driver in different days, rather than the widely employed single distribution model. To demonstrate the merit of this new model, we consider value-at-risk and mean-variance battery capacity design problems for BEV, with respect to conventional single and new mixture distribution models of DVMT. Testing results indicate that the mixture distribution model better leads to better solutions to satisfy various drivers.

The frequent and inappropriate use of antibiotics aggravate the variation and evolution of multidrug-resistant bacteria, posing a serious threat to public health. Nosiheptide (NOS) has excellent lethality against a variety of Gram-positive bacteria, however the physical and chemical drawbacks hamper its routine application in clinical practice. In this study, by using NOS as the starting material, a total of 15 NOS analogues (2a-4e) were semi-synthesized via its dehydroalanine residue reacting with monosubstituted anilines. In vitro antimicrobial susceptibilities of NOS and its analogues against two methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) clinical isolates were determined by broth microdilution assay to determine the minimum inhibitory concentration (MIC). Antimicrobial susceptibility testing data shown that most of the NOS analogues had a better antibacterial effect than the parent compound, with compound 3c exhibiting the highest antibacterial activity against VRE (MIC = 0.0078 mg/L) and MRSA (MIC 0.0039 mg/L). Molecular docking of synthetic compounds was also performed to verify the binding interactions of NOS analogues with the target. Our data indicated that compound 3c possesses stronger and more complex intermolecular force than other analogues, which is consistent with the results of the biological activity evaluation. Overall, this study identified a number of potential antibacterial NOS analogues that could act as potent therapeutic agents for multidrug-resistant bacterial infections.

NosN is a radical S-adenosylmethionine protein observed in the biosynthesis of the bicyclic thiopeptide nosiheptide. Insights are provided in terms of the timing of NosN action, its catalytic mechanism, and its role in side ring formation. Beyond being a methyltransferase, NosN transforms a polythiazolyl peptide intermediate by functionalizing the S-conjugated indolic moiety to selectively build a C1 unit, form an ester linkage to the thiopeptide framework, and establish the side ring system specific for nosiheptide.

Supplementary_Table_1 for Genetic Variant of NFIB is Associated With the Metastasis of Osteosarcoma in Chinese Population by Leilei Xu, Jun Ni, Yongjie Wang, Yang Dong and Shoufeng Wang in Technology in Cancer Research & Treatment

Difluoromethylthiolation of aryldiazonium salts under photocatalytic conditions with a shelf-stable, easily prepared and inexpensive reagent, PhSO2SCF2H was described. A variety of difluoromethylthioethers were obtained utilizing aryldiazonium salts containing different functional groups. Aryldiazonium salts with a heteroarene moiety were tolerated. Fluorescence quenching experiments indicated that both oxidative and reductive quenching cycles occurred during this process.

Rh(III)-catalyzed C(sp

OBJECTIVE To compare the clinical effects of modified uvulopalatopharyngoplasty (UPPP) with low-temperature plasma with selective nasal cavity vasodilatation with tongue volume reduction for obstructive sleep apnea/hypopnea syndrome (OSAHS). METHODS A retrospective analysis based on 156 patients with serious OSAHS was used for the evaluation. These patients were divided into 2 groups according to surgery methods according to 1:1.s. The patients in observation group accepted modified UPPP with low-temperature plasma and selective nasal cavity vasodilatation with tongue root volume reduction on the basis of fully preparation for surgery, while the patients in the control group accepted normal treatment. The clinic effects, operative complications, postoperative relapse, and other indexes were compared. RESULT After 6 months of follow-up visit, the general effective rates of the observation group and control groups were 80.77% and 61.54%, the difference was statistically significant (P

The quinaldic acid (QA) moiety in the side ring of thiostrepton (TSR), which can be modified regioselectively via precursor-directed mutational biosynthesis, was proven to be biologically relevant but tunable, affecting TSR's outstanding antibacterial activities. In this study, we sought to obtain TSR derivatives with varying amino acid residues connected to the QA moiety. The generation of these TSR derivatives relied on single “base”-based mutagenesis, and six new TSR-type compounds were obtained. Moreover, the simultaneous mutation of Ile1 and Ala2 in the TSR side ring resulted in a naturally occurring compound, siomycin (SIO), together with a new component, SIO-Dha2Ser. The anti-infection assays indicated that all of these new compounds could act as both antimicrobial agents and autophagy inducers, and these two kinds of activities can also be separated via regioselective modifications on the TSR side ring.

The double-mutant strain Streptomyces laurentii ΔtsrB/T was designed and constructed based on a recent understanding regarding the structure–activity relationship of thiostrepton (TSR) against prokaryotic pathogens. Five new C-terminally methylated TSR (CmTSR) derivatives that varied in the side-ring structure were obtained via the chemical feeding of quinaldic acid (QA) analogs. These derivatives provide new insights into the tolerance of QA incorporation in TSR biosynthesis. Certain members of the tested TSR derivatives, meanwhile, exhibited much better antibacterial activities than all currently known thiopeptide antibiotics.

Through investigating and comparing the fatigue behavior of an as-cast Mg–7%Gd–5%Y–1%Nd–0.5%Zr alloy in both laboratory air and 3.5 wt.% NaCl solution, the effect of corrosion attack on fatigue crack initiation has been disclosed. The S–N curves showed that the fatigue strength in air was 120 MPa and not sensitive to the loading frequency, whereas the fatigue strength in NaCl solution decreased from 80 MPa to 60 MPa with the loading frequency decreasing from 20 Hz to 5 Hz. Observations to fracture surfaces demonstrated that in air, fatigue cracks preferentially initiated at the oxide inclusions. However, the fatigue crack initiation in NaCl solution was associated with corrosion pits. Moreover, multiple fatigue cracks initiated at pits on fracture surfaces of corrosion fatigue failed samples when the loading frequency decreased to 5 Hz. Based on the measured “defect area” of oxide inclusions, the predicted fatigue strength in air could be well fitted with the experimental data. However, due to the occurrence of hydrogen embrittlement and crack initiation at multiple sites, the fatigue strength of samples tested in NaCl solution cannot be predicted. Keywords: Mg alloy, Corrosion, Cyclic loading, Fatigue crack initiation, Fatigue behavior

The microstructural evolution, corrosion resistance and mechanical properties of an as-forged Mg–6.7%Zn–1.3%Y–0.6%Zr alloy before and after solid solution treatment (T4) were investigated. Results revealed that the proposed T4 treatment can improve corrosion resistance of the alloy. Based on the microstructural observations, such improvement in corrosion resistance incurred by the T4 treatment was mainly ascribed to the elimination of the inhomogeneous distribution associated with the MgZn 2 precipitates formed during hot forging process. However, due to the limited precipitation of nano-scale I-Mg 3 Zn 6 Y particles, the strength of the T4 treated specimen was slightly degraded.

Thiostrepton is a potent archetypal thiopeptide antibiotic. According to its mechanism known to target bacterial ribosome, we show here a rational design upon modeling of this molecule into the ribosome complex and an effective biosynthesis of new thiopeptide antibiotics through regioselective modifications. The resulting derivatives exhibit a series of anticipated and unanticipated pharmaceutical advantages, including improvement in activity against a number of drug-resistant pathogens and in water solubility that has largely affected the clinical use of thiostrepton.

Exosomes are extracellular vesicles with diameters of 30–100 nm that are key for intercellular communication. Almost all types of cell, including dendritic cells, T cells, mast cells, epithelial cells, neuronal cells, adipocytes, mesenchymal stem cells, and platelets, can release exosomes. Exosomes are present in human body fluids, such as urine, amniotic fluid, malignant ascites, synovial fluid, breast milk, cerebrospinal fluid, semen, saliva, and blood. Exosomes have biological functions in immune response, antigen presentation, intercellular communication, and RNA and protein transfer. This review provides a brief overview of the origin, morphological characteristics, enrichment and identification methods, biological functions, and applications in tissue engineering and neurological diseases of exosomes.

Let \(S\) be a semigroup and “\(*\)” a unary operation on \(S\) which satisfies the following identities $$\begin{aligned} xx^*x=x, x^*x x^*=x^*, x^{***}=x^*, (xy^*)^*=y^{**}x^*, (x^*y)^*=y^*x^{**}. \end{aligned}$$ Then, \(S^*=\{x^*|x\in S\}\) is called a regular\(*\)-transversal of \(S\) in the literatures. Following Munn and Hall’s idea, in this paper we construct fundamental regular semigroups with quasi-ideal regular \(*\)-transversals by which fundamental representations of regular semigroups with quasi-ideal regular \(*\)-transversals are obtained.

This study aimed to evaluate the biological functions of excision repair cross complementation goup 1 (ERCC1) in cell proliferation, cell cycle, invasion and cisplatin response of non-small cell lung cancer (NSCLC) cells. Firstly, ERCC1 gene was successfully transfected into H1299 cells by gene cloning and transfection techniques. Then, cell proliferation was determined with the cell growth curve and colony-forming assays. Flow cytometry (FCM) was employed to investigate the cell cycle distribution. The ability of cell invasion was estimated by means of Matrigel invasion assays. Response of NSCLC cells to cisplatin was detected utilizing MTT assays, and the intracellular drug concentrations were determined by the high performance liquid chromatography (HPLC) analysis. Expression of the two cell membrane proteins, P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP), was also evaluated utilizing FCM technique. By contrast, ERCC1 expression in the NSCLC A549 cells was silenced by small interfering RNA (siRNA) through RNAi technique. In addition, the cytotoxic effect of cisplatin on A549 cells was detected by MTT assays. In the present study, the results demonstrated that ERCC1 had no effect on cell proliferation, cell cycle and the ability of invasion, but showed significant impact on cisplatin response of the NSCLC H1299 cells. Furthermore, siRNA-induced suppression of ERCC1 evidently enhanced sensitivity to cisplatin of NSCLC A549 cells. Therefore, it is confirmed that ERCC1 is a chemotherapy-tolerating gene and a promising predictor in tailoring chemotherapy of NSCLC.

A new chiral manganese complex (C1) bearing a tetradentate nitrogen ligand containing chiral bipyrrolidine and benzimidazole moieties was prepared. The structure of C1 was confirmed by ESI-MS and crystallography. This manganese complex is an active catalyst for the asymmetric epoxidation of various olefins with excellent conversion (up to 99 %) and high enantiomeric excess (up to 96 % ee) with hydrogen peroxide as the oxidant in the presence of 2-ethylhexanoic acid or acetic acid. Compared with previous structurally similar manganese complexes with different diamine backbones (C2, cyclohexanediamine; C3, diamine from L-proline), C1 showed improved asymmetric induction, especially for simple olefins such as styrene derivatives and substituted chromene. The possible reasons for the improvement of the ee values are discussed in the text on the basis of the crystal structures of the manganese complexes.

Thiostrepton, a natural peptide macrocycle, is of great interest due to its structural complexity and numerous biological activities, including anti-bacterial, anti-tumor, and anti-plasmodial activities. The quinaldic acid (QA) moiety-containing side ring (loop 2) was proven to play an important role in carrying out these functions. Previously, we proposed biosynthetic logic for thiostrepton loop 2 and demonstrated the formation mechanism of QA. Herein, we report the discovery and efficient synthesis of a biologically active alkaloid, that is, a key intermediate involved in the thiostrepton biosynthetic pathway. A chemo-enzymatic method was performed to synthesize the molecule, and a series of analogs were prepared for bioassays, which included the examination of anti-bacterial and anti-tumor activities.

Background context As the biomechanical foundation of the spine, the pelvis was found to display rotation in the transverse plane in adolescent idiopathic scoliosis (AIS). However, the possible factors influencing the pelvic axial rotation (PAR) and its mechanism in patients with AIS remain unclear. Purpose To characterize the PAR in AIS patients with right major thoracic (MT) or major left thoracolumbar/lumbar (TL/L) curve and to explore the associated influencing factors and probable mechanism of compensation by analyzing the association between PAR and other spinal radiographic parameters. Study design Retrospective study. Patient sample All patients with the primary diagnosis of AIS from January 2008 to November 2009 were retrieved from our scoliosis database. Outcome measures Age, Cobb angle, and apex rotation of the main curve and the compensatory curve, curve flexibility, and PAR. Methods One-hundred thirty-two patients with right MT (14.7±1.8 years, 48±6.9°) and 83 patients with left major TL/L (14.7±1.5 years, 46±6.6°) were retrospectively reviewed. On standing full-spine posteroanterior radiographs, the PAR was quantified by the left/right hemi-pelvis width ratio (L/R ratio); then the subjects in both MT and major TL/L groups were divided into two subgroups: L/R ratio ≤1 (pelvis rotated to the right, R-PAR group); and L/R ratio >1 (pelvis rotated to the left, L-PAR group). Comparisons of all variables were performed between the L- and R-PAR subgroups; correlation and regression analysis were carried out to identify the influencing factors of PAR. Results The majority of the MT and major TL/L patients (75.8% vs. 60.2%) displayed right pelvic rotation, which was in the same direction as the thoracic curve. The incidence of R-PAR was greater in the MT patients than the major TL/L ones (p=.016). Lumbar flexibility in MT patients with R-PAR was greater than in MT patients with L-PAR (0.96±0.27 vs. 0.81±0.33, p=.038), which was contrary to the findings in the major TL/L patients (L-PAR>R-PAR, 0.79±0.15 vs. 0.70±0.22, p=.024). In the MT patients with R-PAR, the L/R ratio showed significant positive correlations with the lumbar Cobb angle (r=0.424) as well as with the apex rotation (r=0.488), which was further identified as an influencing factor (R=0.418) of the PAR. Significant positive correlations between L/R ratio and thoracic apex rotation (r=0.361) also were detected. Conclusion The majority of AIS patients with right MT or left major TL/L curves were found to have PAR to the right, in the same direction as the thoracic curve. The lumbar flexibility and apex rotation significantly influenced the PAR direction and magnitude. Moreover, the pelvis might be involved in compensation for the MT deformity through its connection with the lumbar spine.

Serum Epstein-Barr virus DNA has been approved for diagnosing nasopharyngeal carcinoma (NPC). The goal of this meta-analysis was to evaluate the clinical value of the serum Epstein-Barr virus DNA in the diagnosis of NPC. The PubMed, Embase, Web of Knowledge, Chinese Wanfang Med Online, and National Knowledge Infrastructure (CNKI) databases were searched to identify suitable studies. The pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) of the serum Epstein-Barr virus DNA for the diagnosis of NPC were calculated. Summary receiver operating characteristic curves were used to summarize overall test performances. Meta-Disc 1.4 and Stata 12.0 softwares were used to analyze the data. A total of 2,520 patients from ten trials were subjected to meta-analysis. The summary estimates of the serum Epstein-Barr virus DNA for NPC diagnosis were as follows: sensitivity 0.69 (95 % confidence interval (CI) 0.65-0.72), specificity 0.84 (95 % CI = 0.82-0.86), LR + 4.81 (95 % CI = 2.94-7.88), LR - 0.25 (95 % CI = 0.13-0.48), DOR 24.65 (95 % CI = 12.64-48.07), and area under the summary receiver operator characteristic (SROC) curve (AUC) was 0.8979. Our study demonstrates that the serum Epstein-Barr virus DNA could be a useful tumor marker for NPC diagnosis.

The cobalt–salen complex (C1:[(salen)Co3+(OAc)]; salen= N,N′-bis(salicylidene)ethylenediamine, OAc=acetate) was found to efficiently promote the hydration of terminal alkynes to give methyl ketones in the presence of the H2SO4 cocatalyst. In addition, the one-pot transformation of alkynes into chiral alcohols through tandem catalysis by catalyst C1 coupled with a ruthenium–TsDPEN complex (C3: [(R,R-TsDPEN)Ru2+(cymene)]; TsDPEN=(1R,2R)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine, cymene=1-methyl-4-(1-methylethyl)benzene) catalyst was realized with excellent yields and enantioselectivities.

A benzimidazole-based nonheme manganese complex efficiently catalyzes benzylic, aliphatic C-H as well as tertiary C-H oxidation with hydrogen peroxide as the oxidant in the presence of acetic acid as additive. (18)O labeling experiments suggest the reaction may proceed via a high-valent manganese-oxo intermediate.

Nosiheptide is an archetypal thiopeptide antibiotic, possessing a characteristic macrocyclic core that contains a 6-membered heterocycle central to multiple azol(in)es and dehydroamino acids. The discovery of the ribosomal origin of thiopeptides revealed a unifying theme, showing that the structural complexity arises from post-translational modifications (PTMs) of precursor peptides. Thiopeptide framework formation proceeds via cyclodehydration/dehydrogenation (for azol(in)es), dehydration (for dehydroamino acids), and cycloaddition (for the central heterocycle domain). This common process has not been reproduced in vitro, partly due to the poorly understood logic of thiopeptide biosynthetic pathways. Utilizing nosiheptide biosynthesis as a model system, we herein consider how nature coordinates a number of highly interwined, common and specific PTMs to accomplish the complexity of ribosomally synthesized and post-translationally modified peptides.

An efficient and mild method is reported for the construction of β-chlorotetrahydrofuran derivatives by 5-endo chlorocycloetherification of homoallylic alcohols. The system employs sulfuryl chloride as the chlorinating agent under catalyst-free conditions. A variety of homoallylic alcohols with aryl or alkyl substituents were smoothly converted into β-chlorotetrahydrofurans in yields up to 98%.

The manganese and iron complexes with the tetradentate N ligand (1R,2R)-N,N'-dimethyl-N,N'-bis(1-methyl-2-benzimidazolylmethyl)cyclohexane-1,2-diamine have been synthesized and characterized. cis- configuration. Both the manganese and iron complexes are active catalysts for the asymmetric epoxidation of olefins with H 2 O 2 as an oxidant and acetic acid as an additive. Up to 96% ee was observed for the epoxidation of α,β-unsaturated ketones at -20 ℃.

We give necessary and sufficient conditions for various vertex-transitivity of Cayley graphs of the class of completely 0-simple semigroups and its several subclasses. Moreover, the question when the Cayley graphs of completely 0-simple semigroups are undirected is considered.

Objective Treatment of distal femoral fracture in post-polio patients is difficult because the bone is usually osteopenic, small and deformed. This retrospective study aimed to investigate the outcomes of distal femoral fracture in post-polio patients treated by locking compression plates (LCP). Methods The medical records of 19 post-polio patients (mean age 49 years at time of surgery) were reviewed and intraoperative data retrieved. Fracture union and callus formation were evaluated on radiographs taken at each postoperative visit. Functional outcome assessments included range of motion and Hospital for Special Surgery (HSS) score of the ipsilateral knee joint. Results Sixteen femoral fractures occurred in the poliomyelitis-affected limbs. The mean duration of operation was 86 min and mean blood loss 120 mL. All fractures healed (mean, four months) but union was delayed in one. At the final follow-up 2 yrs after surgery, the mean range of knee flexion was 105° (range, 90°–130°), and mean HSS score 76 points (range, 60–93). There were no cases of nonunion, implant cutout, or other complications. Conclusions LCP provides stable fixation of distal femoral fractures in post-polio patients. Bony union and good functional outcomes are achieved, but delayed union and minimal callus may occur.

MSTS questionnaire in English version. (DOCX 17 kb)

The pelvis as the biomechanical foundation of spine, plays an important role in the balance of the stance and gait through the multi-link spinal-pelvic system. If the pelvic axial rotation (PAR) exists in adolescent idiopathic scoliosis (AIS) patients, it should theoretically have some effects on the body balance.To explore the probable effects of preoperative PAR on the spinal balance in coronal plane in AIS patients with main thoracolumbar/lumbar (TL/L) curve after posterior spinal instrumentation.Thirty-eight AIS patients (age: 15 ± 1.5 years) with main TL/L curve (51° ± 6.2°) were recruited retrospectively into this study. The mean follow-up period was 27 months (24-36 months). Standing full spine posteroanterior radiographs were taken preoperatively, 3 month and 1 year postoperatively, and at last follow-up. The convex/concave ratio (CV/CC ratio) of the anterior superior iliac spine laterally and the inferior ilium at the sacroiliac joint medially was measured on posteroanterior radiographs. According to the preoperative CV/CC ratios, the patients were divided into two groups: normal group (N-group: 0.95 ≤ CV/CC ≤ 1.05); and the asymmetrical group (A-group: CV/CC0.95, or1.05).In all the patients, the 3-month-postoperative CV/CC ratio (1.026 ± 0.087) was significantly different from the preoperative CV/CC ratio (0.969 ± 0.095, P0.001), indicating that the pelvis had rotated in the opposite direction of the corrective derotation load applied to the TL/L spine after surgery. No significant change was found in the CV/CC ratio from 3-month-postoperative to the last follow-up (1.013 ± 0.103, P0.05). There was no significant difference in the demographic, phenotypic, and treatment variables between the N- (n = 16) and A-groups (n = 22) (P0.05). However, more coronal decompensation occurred in the A-group after surgery (36.4 vs. 0.0 %, P = 0.013): two patients having trunk translation, three having lower instrumented vertebra (LIV) translation, and one having LIV tilt; meanwhile, one patient having both LIV translation and LIV tilt, and one having both trunk translation and LIV tilt.The present study confirmed the existence of PAR in AIS patients, and indicated that the pelvis would experience an active rebalancing in the transverse plane within 3 months after spinal correction, and since then, its position would remain stable. Moreover, TL/L-AIS patients with preoperative asymmetrical PAR probably had greater risk of coronal decompensation postoperatively.

BACKGROUND The association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and breast cancer risk has been extensively explored, but their results are conflicting rather than conclusive. To clarify the precise effects of MTHFR polymorphisms on the risk of breast cancer, a systemic review and most comprehensive meta-analysis of all available studies relating MTHFR rs1801133 gene polymorphism to the risk of breast cancer was conducted. METHODS Eligible articles were identified by search of databases including Medline (Mainly PubMed), Embase, Web of Science, Chinese Biomedical Literature database (CBM), CNKI and Wanfang Medical databases. Crude ORs with 95% CIs were used to assess the strength of association. RESULTS Finally, a total of 83 studies with 35,029 cases and 38,990 controls were included. Overall, MTHFR rs1801133 gene polymorphism was proved to contribute to the risk of breast cancer under all genetic models (TT vs. CC: Pheterogeneity

Side-ring-modified thiostrepton (TSR) derivatives that vary in their quinaldic acid (QA) substitution possess more potent biological activities and better pharmaceutical properties than the parent compound. In this work, we sought to introduce fluorine onto C-7′ or C-8′ of the TSR QA moiety via precursor-directed mutational biosynthesis to obtain new TSR variants. Unexpectedly, instead of the target product, the exogenous chemical feeding of 7-F-QA into the ΔtsrT mutant strain resulted in a unique TSR analog with an incomplete side-ring structure and an unoxidized QA moiety (1). Accordingly, two cytochrome P450 genes, tsrP and tsrR, were in-frame deleted to elucidate the candidate responsible for the monooxidation of the QA moiety in TSR. The unfluorinated analog of compound 1 that was thus isolated from ΔtsrP (2) and the abolishment of TSR production in ΔtsrR revealed not only the biosynthetic logic of the TSR side-ring but also the essential checkpoint in TSR maturation before macro-ring closure.