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This study has identified two polymer additives that when added in low concentrations can be used to reliably prevent incongruent melting of sodium acetate trihydrate (SAT) when temperature-cycled over multiple thousands of melting and freezing cycles. The polymers appear to act as crystal-habit modifiers that at sub-optimal concentrations dramatically alter the morphology of any anhydrous sodium acetate that may be formed, and at higher concentrations completely suppress precipitation of anhydrous sodium acetate. In situ X-ray powder diffraction experiments show that the active nucleator for SAT is Na2HPO4·2H2O, and that the mechanism of thermally induced deactivation is dehydration in solution to form anhydrous Na2HPO4. Based on these studies, new formulations of SAT have been developed that demonstrate consistent and reliable performance as phase-change materials for heat-storage applications.

Background Cervical cancer (CC) is the one of most common malignant gynecological tumors, which is characterized with the high mortality and recurrence rate. Previous studies have elucidated the oncogenic role of small nucleolar RNA host gene 6 (SNHG6) in some types of human cancers, whereas it is unclear whether it functions as an oncogene in CC. This study was aimed at unveiling the role of SNHG6 in CC. Methods qRT-PCR analysis was implemented to evaluate the expression levels of SNHG6, miR-485-3p and STYX in CC cells. RNA pull down assay and luciferase reporter assay were conducted to verify the interaction between miR-485-3p and SNHG6 or STYX. Functional assays, such as colony formation assay, JC-1 assay and TUNEL assay were applied to detect the biological behaviors of CC cells. The resistance of CC cells to radiation was evaluated by colony formation assay. Results SNHG6 was expressed at a high level in CC cells. Silenced SNHG6 suppressed cell proliferation but promoted cell apoptosis. Additionally, silenced SNHG6 could sensitize CC cells to radiation treatment. miR-485-3p could bind to both SNHG6 and STYX. Knockdown of miR-485-3p or overexpression of STYX could abolish the effects of SNHG6 silencing on CC cell growth. Conclusions LncRNA SNHG6 enhances the radioresistance of CC cells and promotes CC cell growth by sponging miR-485-3p to release STYX.

Background Mycotoxins have received much attention due to their potential harmful impact on humans. Increasing awareness of environmental protection and food safety prompts the use of eco-friendly and biosafe strategies for mycotoxin elimination in food production. Scope and approach Mycotoxin adsorption by microorganisms has become increasingly promising due to its environmental friendliness and efficiency. This review is mainly focused on discussing different kinds of microorganisms able to adsorb mycotoxins, exploring the main mechanisms of yeast and lactic acid bacterial bioadsorption actions involving cell wall physical structure, chemical components, and their complicated interactions with mycotoxins. Moreover, industrial applications and future research needs are also proposed. Key findings and conclusions Yeasts and lactic acid bacteria have the great advantages of their adsorption capability and being food security friendly, and their complicated interactions with mycotoxins indicate that cell wall structural integrity, physical structure and morphology, and chemical components all play important roles in the adsorption process. On this basis, future approaches may rely on combinations of different microorganism to provide complementary advantages in mycotoxin degradation and adsorption.

We report the unexpected pressure-induced and time-dependent nucleation and crystallisation of n-pentane from a 1 : 1 mixture of n-pentane and iso-pentane. The crystal structure of n-pentane at 3.3 GPa is reported; the 19.6% decrease in volume up to 3.3 GPa is caused by the significant reduction of voids within the structure. The study has wider implications for the separation of mixtures of organic compounds that have similar melting and boiling points, as well as the use of a 1 : 1 mixture of n-pentane and iso-pentane as a pressure-transmitting medium in high-pressure diffraction experiments.

Microbial competition for carbon sources is associated with disease suppression, and continuous mono-cropping stimulates certain patterns of carbon deposits. In this study, we investigated five fields from three ginger mono-cropping durations (over 35 years, approximately 15 years and 3 years) and two disease conditions (wilt-suppressive and wilt-conducive) at two collection time points (fallow and harvest). We measured the bacterial community and overall microbial carbon metabolism ability using high-throughput sequencing and Biolog EcoPlates. The results showed that the metabolic capabilities of soil microbes at harvest time were higher than at fallow time. The distribution of the bacterial community and the soil microbial metabolic diversity were significantly affected by both factors of cropping years and disease conditions at harvest time. Moreover, potentially beneficial microbes more enriched in wilt-suppressive soils than in wilt-conducive soils and l -arginine and 4-hydroxybenzoic acid were significantly metabolized in suppressive samples. We further confirmed that l -arginine and 4-hydroxybenzoic acid were only slightly metabolized by the pathogen. Taken together, these results suggest that the addition of l -arginine could enrich the beneficial microbes, while metabolism of 4-hydroxybenzoic acid could indicate the disease conditions of soil.

Variable-temperature single-crystal and powder X-ray diffraction techniques have been used to study the thermal and mechanical decomposition of the acetonitrile solvate of the cocrystal formed betw...

Surface molecularly imprinted polymer of solanesol (SA-SMIP) was prepared by reversed phase suspension polymerization using modified titanium dioxide (TiO2) as carrier, and operation conditions were investigated and optimized. Structures of modified TiO2 and SA-SMIP obtained at optimal conditions were characterized by Fourier transform infrared spectrometer adopting original TiO2 and non-surface molecularly imprinted polymer as reference. The SA-SMIP synthesized under optimal conditions displayed an excellent recognition of SA from the mixture of SA and triacontanol. The maximum separation degree of SA was 2.90. Finally, the adsorption kinetics and isotherm were investigated and analyzed. Adsorption kinetics results indicated that the adsorption of SA-SMIP to SA was a pseudo-second order process, and the adsorption of beginning and later stages was controlled by homogeneous particle diffusion and adsorption reaction process, respectively. Adsorption isotherm results documented hereby were two sorts of bonding sites, complete imprinted cavities and defective imprinted cavities. The adsorption for two bonding sites could be well lined up with the Langmuir model.

Long-term monoculture cropping is usually accompanied by soil acidification and microbial community shifts. Soil aluminum ions are dissolved under acidic condition (pH < 5.0), and the resulting aluminum bioavailability can cause toxic effects in plants. In this study, we investigated the bacterial community compositions and aluminum toxicity in fields monocultured with ginger for 35 years, 15 years, and 1 year. Within these fields are ginger plants without and with ginger bacterial wilt disease. The results confirmed that the degree of aluminum toxicity in the diseased soil was more severe than that in the healthy soil. Continuous cropping can significantly increase the bacterial diversity and change the bacterial community composition of ginger rhizosphere soil. The relative abundance of plant growth-promoting rhizobacteria (PGPRs) was increased in the soils used for the continuous cropping of ginger. Additionally, aluminum toxicity had a significant positive correlation with Bacillus, Pseudomonas, Arthrobacter, and Serratia in healthy soils. Based on these results, aluminum stress may stimulate the increase of PGPRs (Bacillus, Pseudomonas, Arthrobacter, and Serratia), thereby alleviating ginger aluminum toxicity and bacterial wilt in extremely acidic soil (pH < 4.5).

The equation of state, dynamical properties, and molecular-scale structure of squalane and mixtures of poly-α-olefins at room temperature are studied with a combination of state-of-the-art, high-pressure experiments and molecular-dynamics simulations. Diamond-anvil cell experiments indicate that both materials are non-hydrostatic media at pressures above ∼1 GPa. The equation of state does not exhibit any sign of a first-order phase transition. High-pressure x-ray diffraction experiments on squalane show that there are no Bragg peaks, and hence, the apparent solidification occurs without crystallization. These observations are complemented by a survey of the equation of state and dynamical properties using simulations. The results show that molecular diffusion is essentially arrested above about 1 GPa, which supports the hypothesis that the samples are kinetically trapped in metastable amorphous-solid states. The shear viscosity becomes extremely large at very high pressures, and the coefficient governing its increase from ambient pressure is in good agreement with the available literature data. Finally, simulated radial distribution functions are used to explore the evolution of the molecular-scale structure with increasing pressure. Subtle changes in the short-range real-space correlations are related to a collapse of the molecular conformations with increasing pressure, while the evolution of the static structure factor shows excellent correlation with the available x-ray diffraction data. These results are of indirect relevance to oil-based lubricants, as the pressures involved are comparable to those found in engines, and hence, the ability of lubricating thin films to act as load-bearing media can be linked to the solidification phenomena studied in this work.

Bacteriophage T7 infects Escherichia coli and evades the host restriction/modification system. The Ocr protein of T7 was shown to exist as a dimer mimicking DNA and to bind to host restriction enzymes, thus preventing the degradation of the viral genome by the host. Here we report that Ocr can also inhibit host transcription by directly binding to bacterial RNA polymerase (RNAP) and competing with the recruitment of RNAP by sigma factors. Using cryo electron microscopy, we determined the structures of Ocr bound to RNAP. The structures show that an Ocr dimer binds to RNAP in the cleft, where key regions of sigma bind and where DNA resides during transcription synthesis, thus providing a structural basis for the transcription inhibition. Our results reveal the versatility of Ocr in interfering with host systems and suggest possible strategies that could be exploited in adopting DNA mimicry as a basis for forming novel antibiotics., eLife digest Bacteria and viruses have long been fighting amongst themselves. Bacteriophages are a type of virus that invade bacteria; their name literally means ‘bacteria eater’. The bacteriophage T7, for example, infects the common bacteria known as Escherichia coli. Once inside, the virus hijacks the bacterium’s cellular machinery, using it to replicate its own genetic material and make more copies of the virus so it can spread. At the same time, the bacteria have found ways to try and defend themselves, which in turn has led some bacteriophages to develop countermeasures to overcome those defences. Many bacteria, for example, have restriction enzymes which recognise certain sections of the bacteriophage DNA and cut it into fragments. However, the T7 bacteriophage has one well-known protein called Ocr which inhibits restriction enzymes. Ocr does this by mimicking DNA, which led Ye et al. to wonder if it could also interrupt other vital processes in a bacterial cell that involve DNA. Transcription is the first step in a coordinated process that turns the genetic information stored in a cell’s DNA into useful proteins. An enzyme called RNA polymerase decodes the DNA sequence into a go-between molecule called messenger RNA, and it was here that Ye et al. thought Ocr might jump in to interfere. To begin, Ye et al. examined the structure of Ocr when it binds to RNA polymerase using an imaging technique called cryo-electron microscopy. Ocr has been well-studied before, its structure previously described, but not when attached to RNA polymerase. The analysis showed that Ocr gets in the way of specific molecules, called sigma factors, that show RNA polymerase where to start transcription. Ocr binds to RNA polymerase in exactly the same pocket as part of sigma factors do, which is also the place where DNA must be to be decoded to make messenger RNA. Ye et al. then performed experiments to show Ocr interfering with binding to RNA polymerase did indeed disrupt transcription. This means Ocr is quite versatile as it interferes with the RNA polymerase of the bacterial host and its restriction enzymes. Ocr’s strategy of mimicking DNA to interrupt transcription could be adopted as an approach to develop new antibiotics to stop bacterial infections. DNA transcription is an essential cellular process – without it, no cell can replicate and survive – and RNA polymerase is already a validated target for drugs. Following Ocr’s lead could provide a new way to stop infections, if the right drug can be designed to fit.

To study the influence of the preparation method on Cu active sites and the reaction pathway in NO reduction by NH3 over Cu–SSZ-13, three kinds of catalysts (Cu ion-exchanged SSZ-131, one-pot synthesis Cu–SSZ-132, and Ce0.017–Fe0.017/Cu–SSZ-13 [Ce and Fe ion exchange on the basis of Cu–SSZ-132]) were prepared. In situ diffuse reflectance infrared Fourier transform spectroscopy and H2 temperature program reduction were used to study the differences in the reaction pathways and Cu active sites over the three kinds of catalysts. Density functional theory was employed to study the effect of active sites on the reaction pathway. In situ DRIFTS showed that the reaction pathway on Cu–SSZ-131 during NO oxidation was different from that on Cu–SSZ-132 and Ce0.017–Fe0.017/Cu–SSZ-13. The difference was that intermediate NO2 was involved in the selective catalytic reduction reaction on Cu–SSZ-131, whereas NO2 was not found during the reaction process on Cu–SSZ-132 and Ce0.017–Fe0.017/Cu–SSZ-13. H2–TPR studies revealed that the three catalysts had different Cu active sites, which were located in the six-membered ring, eight-membered ring, and CHA cage. On the basis of DFT studies, NO and O2 were more conducive to form nitrate when the Cu species was on the six- and eight-membered rings; by contrast, NO and O2 were more conducive to form NO2 in the cage. These results showed that different preparation methods led to various Cu active sites, and varying Cu active sites could lead to different NO oxidation processes.

Mycotoxins are secondary metabolites produced by fungal species and have been reported to be carcinogenic, genotoxic, teratogenic, nephro- and hepatotoxic. Economic losses and health concerns due to mycotoxins occur at all levels of food and feed production, and this has attracted research interest towards exploring novel approaches to decontaminate and/or detoxify mycotoxin-contaminated food and feed. Therefore, we reviewed various strategies for the detoxification of mycotoxins, including pre-harvest prevention strategies and post-harvest detoxification procedures. Strategies for pre-harvest prevention include appropriate environmental factors, good agricultural and manufacturing practices, and favourable storage practices. For post-harvest detoxification strategies, physical, chemical, biological and other developing innovative strategies are discussed. This review is meant to be beneficial to the food industry and to contribute to assuring pre- and post-harvest management and processing practices that maximize consumer safety.

Obtaining the fingerprints of polysaccharides was known to be notoriously difficult by ambient mass spectrometry due to their resistance for desorption and ionization. Ambient mass spectrometry technology has recently been recognized as a quick analysis tool for obtaining fingerprints, which is attributed to its characteristics of no sample pretreatment and easy operation under atmospheric pressure. However, it still remains a challenge for accurate identification of the fingerprints of macromolecular polysaccharides by ambient micro-fabrication glow discharge plasma (MFGDP). In this study, a simplified methylation method was introduced to realize rapid analysis of polysaccharide mixture by MFGDP with the assistance of a temperature-programmed system (TPS). At the optimal temperature of TPS, oligosaccharides, plant polysaccharides and polysaccharide mixtures were all well characterized by TPS-MFGDP. In the proposed method, the characteristic [M + NH4] + adduct ions of oligosaccharides ions of oligosaccharides that are difficult for other ambient mass spectrometric methods were abundantly produced, making it possible to simultaneously identify a mixture of five or more polysaccharides. In addition, a supervised classification model which based on MS spectra, was used to classify seven typical hypoglycemic polysaccharides with excellent sensitivity, specificity and accuracy, indicating the good classification performance of the RF model constructed. Thus, the proposed mass spectroscopic method provides a cost effective, accurate and high throughput tool for identification and classification of polysaccharides, which is beneficial for studying the biological activity of polysaccharides.

This work reports a new acetonitrile (ACN)-solvated cocrystal of piroxicam (PRX) and succinic acid (SA), 2C15H13N3O4S·0.5C4H6O4·C2H3N or PRX:SA:ACN (4:1:2), which adopts the triclinic space group P\overline{1}. The outcome of crystallization from ACN solution can be controlled by varying only the PRX:SA ratio, with a higher PRX:SA ratio in solution unexpectedly favouring a lower stoichiometric ratio in the solid product. In the new solvate, zwitterionic (Z) and non-ionized (NI) PRX molecules co-exist in the asymmetric unit. In contrast, the nonsolvated PRX–SA cocrystal contains only NI-type PRX molecules. The ACN molecule entrapped in PRX–SA·ACN does not form any hydrogen bonds with the surrounding molecules. In the solvated cocrystal, Z-type molecules form dimers linked by intermolecular N—H...O hydrogen bonds, whereas every pair of NI-type molecules is linked to SA via N—H...O and O—H...N hydrogen bonds. Thermogravimetry and differential scanning calorimetry suggest that thermal desolvation of the solvate sample occurs at 148 °C, and is followed by recrystallization, presumably of a multicomponent PRX–SA structure. Vibrational spectra (IR and Raman spectroscopy) of PRX–SA·ACN and PRX–SA are also used to demonstrate the ability of spectroscopic techniques to distinguish between NI- and Z-type PRX molecules in the solid state. Hence, vibrational spectroscopy can be used to distinguish the PRX–SA cocrystal and its ACN solvate.

Patulin contamination is a severe issue that restricts the development of the global fruit processing industry. Yeast adsorbs patulin more effectively than other microbial adsorbents, and this adsorption process mainly depends on the function of the cell wall. Additionally, exogenous calcium ions aid in yeast cell wall formation according to reports. Therefore, in the present study, the effect of exogenous calcium concentrations on the cell wall structure and the patulin adsorption capability was studied. We showed that the ability of the yeast to adsorb patulin was strengthened with an increase in exogenous calcium concentrations between 1×10-4 - 1×10-2 mol/L. Moreover, yeast cell wall thickness, β-1,3-glucan content and the activities of the key catalytic enzymes β-1,3-glucanase and β-1,3-glycosyl transferase were all increased within this range. The results indicated that exogenous calcium activates key enzymes and that these enzymes are crucial for cell wall network formation and patulin adsorption capability.ImportanceThe present work illuminates that the exogenous calcium ions could determine the insoluble network structure by regulating key enzyme activities under certain concentrations, thus indirectly influencing the yeast cell patulin adsorption capability. It could enhance patulin adsorption capability of yeast walls and successfully apply to fruit juice industry.

Chloropicrin is widely used to control ginger wilt in China, which have an enormous impact on soil microbial diversity. However, little is known on the possible legacy effects on soil microbial community composition with continuous fumigation over different years. In this report, we used high throughput Illumina sequencing and Biolog ECO microplates to determine the bacterial community and microbial metabolic activity in ginger harvest fields of non-fumigation (NF), chloropicrin-fumigation for 1 year (F_1) and continuous chloropicrin-fumigation for 3 years (F_3). The results showed that microbial richness and diversity in F_3 were the lowest, while the metabolic activity had no significant difference. With the increase of fumigation years, the incidence of bacterial wilt was decreased, the relative abundance of Actinobacteria and Saccharibacteria were gradually increased. Using LEfSe analyses, we found that Saccharibacteria was the most prominent biomarker in F_3. Eight genera associated with antibiotic production in F_3 were screened out, of which seven belonged to Actinobacteria, and one belonged to Bacteroidetes. The study indicated that with the increase of fumigation years, soil antibacterial capacity may be increased (possible reason for reduced the incidence of bacterial wilt), and Saccharibacteria played a potential role in evaluating the biological effects of continuous fumigation. Electronic supplementary material The online version of this article (doi:10.1186/s13568-017-0475-1) contains supplementary material, which is available to authorized users.

A variety of linear and side-chained p-nitrostilbene derivatives with various numbers of bromine atoms were prepared to survey the crystal structural properties, the photoluminescence, and heavy atom effect on the singlet oxygen generation by two-photo absorption (TPA). Single crystals of 4-nitro-4′-(4″-bromo-phenyl-methyl-oxy)-diphenylethylene (C2), 4-nitro-4′-(3″,5″-dibromo-phenyl-methyl-oxy)-diphenylethylene (C3), 4-nitro-4′-(2′,3″,4′,5″,6″-pentabromo-phenyl-methyl-oxy)-diphenylethylene (C4) were obtained, and the structural characteristics were analyzed by X-ray diffraction. One- and two-photon optical properties of the photosensitizers are shown dependence on the numbers of substituted bromine atoms. While TPA cross-sections of the photosensitizers are diminished more considerably, singlet oxygen quantum yields of the photosensitizers are enhanced at some extents by the substituted bromine atoms. Side-chained photosensitizers display correspondingly higher singlet oxygen quantum yields and larger TPA cross-sections than the molecules with single bromine-substituted aromatic segment. Molecular modeling was also performed to reveal the fundamental reasons of the experimental observation. Photooxidation reaction of singlet oxygen with some substrates was employed to confirm singlet oxygen generation under one- and two-photon irradiation.

The growing emergence of antibiotic-resistant bacteria in the food industry needs to be controlled with effective antimicrobials. In this study, bacteriocin MN047 A (BMA) was found to have antibacterial activity against multidrug-resistant bacteria. It was produced by Lactobacillus crustorum MN047, which was first isolated from koumiss, a traditional fermented dairy product from Xinjiang Autonomous Region, China. It was purified by ammonium sulfate precipitation, ion-exchange chromatography, and reversed-phase chromatography. It had a low molecular mass of 1,770.89 Da according to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the sequence was identified as QLPWQILGIVAGMFQA by liquid chromatography-tandem mass spectrometry analysis and MASCOT searching. It was proteinaceous in nature: the bacteriocin was digested by protease but not by α-amylase or lipase. It showed broad pH toleration (pH 2-11), good thermostability, and good storage stability. It had a broad inhibitory spectrum, including both gram-positive and gram-negative bacteria. Growth curve and time-kill kinetics indicated that it was bactericidal to the indicator strains, and this finding was verified by scanning electron microscope and transmission electron microscope after treatment with BMA. As well, BMA halted the growth of Staphylococcus aureus and Escherichia coli in the G1 and G2/M phases according to cell-cycle analysis by flow cytometry, indicating that BMA had comprehensive inhibitory effects against foodborne pathogens.

In this paper, we presented four novel visible light photoinitiating systems, which employed nitro-stilbenzene derivatives as photoinitiators. Visible light photopolymerization of these systems was studied completely. The results showed that the chemical structures of the photoinitiators, photoinduced electron transfer approach, solvent polarity, and monomers played significant effects on the visible light photopolymerization. The electrochemistry of nitro-stilbenzene was dramatically influenced by the linking benzophenone moiety. The cyclic voltammograms of four photoinitiators were determined and discussed. We further estimated the thermodriving force for electron transfer between nitro-stilbenzene and benzophenone. Thermal stabilities of new photoinitators were determined by the analysis of differential scanning calorimetry (DSC) and thermogravimetry (TG) in this paper. Copyright © 2009 John Wiley & Sons, Ltd.

Novel nitro-azobenzene dyes bearing one or two benzophenone branches were proposed and synthesized to improve their photophysical and photochemical properties. The new dyes exhibited double UV/visible bands, and they displayed weak fluorescence emission as excited at 350 nm. Single crystal X-ray diffraction data showed that two phenyl rings of azobenzene was almost coplanar, and the benzophenone part was neither coplanar nor linear connection with azobenzene via ether bridged bond, which have good fit with molecular geometry optimization calculation results. The cyclic voltammeric results of nitro-azobenzene dyes were firstly reported in this paper, which demonstrated that the electrochemical properties of nitro-azobenzene dyes was altered by the substitution of benzophenone part. Thermal stabilities of the new dyes were studied by the analysis of differential scanning calorimetry (DSC) and thermograving (TG) in this paper. Efficient visible-light photoinitiating polymerization of methyl methacrylate (MMA) by the novel nitro-azobenzene dyes was presented and discussed.

To examine if higher intake of isoflavones prior to diagnosis was associated with a positive status of estrogen receptors (ER) and progesterone receptors (PR) in breast tumor tissue, a retrospective study was conducted in 2004 to 2005 in 756 Chinese women with histologically confirmed breast cancer. We administered a food frequency questionnaire by face-to-face interview to assess the intake of the isoflavones daidzein and genistein. Unconditional logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for potential confounders. Comparing the highest to lowest intake quartiles, the adjusted ORs for daidzein were 1.94 (95% CI = 1.20-3.32) and 2.18 (95% CI = 1.28-3.73) for ER positive and PR positive tumors, respectively, in premenopausal patients. The ORs for both ER and PR positive status combined were 2.48 (95% CI = 1.37-4.49) for daidzein and 1.94 (95% CI = 1.21-3.14) for genistein in premenopausal patients with statistically significant tests for trend. There was little or no evidence of associations in postmenopausal patients. We conclude that higher intake of daidzein and genistein before diagnosis was associated with ER and PR positive status in premenopausal Chinese women with breast cancer. The association might confer a more favorable prognosis.

Resistance to chemotherapy is a major obstacle for the effective treatment of cancers. Lin28 has been shown to contribute to tumor relapse after chemotherapy; however, the relationship between Lin28 and chemoresistance remained unknown. In this study, we investigated the association of Lin28 with paclitaxel resistance and identified the underlying mechanisms of action of Lin28 in human breast cancer cell lines and tumor tissues. We found that the expression level of Lin28 was closely associated with the resistance to paclitaxel treatment. The T47D cancer cell line, which highly expresses Lin28, is more resistant to paclitaxel than the MCF7, Bcap-37 or SK-BR-3 cancer cell lines, which had low-level expression of Lin28. Knocking down of Lin28 in Lin28 high expression T47D cells increased the sensitivity to paclitaxel treatment, while stable expression of Lin28 in breast cancer cells effectively attenuated the sensitivity to paclitaxel treatment, resulting in a significant increase of IC50 values of paclitaxel. Transfection with Lin28 also significantly inhibited paclitaxel-induced apoptosis. We also found that Lin28 expression was dramatically increased in tumor tissues after neoadjuvant chemotherapy or in local relapse or metastatic breast cancer tissues. Moreover, further studies showed that p21, Rb and Let-7 miRNA were the molecular targets of Lin28. Overexpression of Lin28 in breast cancer cells considerably induced p21 and Rb expression and inhibited Let-7 miRNA levels. Our results indicate that Lin28 expression might be one mechanism underlying paclitaxel resistance in breast cancer, and Lin28 could be a potential target for overcoming paclitaxel resistance in breast cancer.

This letter reports the influence of branches and bromine substitution of the photosensitizers on one- and two-photon absorption generation of singlet oxygen. Near-infrared femtosecond Ti:squassier laser was utilized to determine two-photon properties of the photosensitizers tuning wavelength from 700 to 880 nm at intervals of 20 nm. One- and two-photon optical and photophysical properties of the photosensitizers show significant dependence on the branches and substituted bromine atoms.