Organocatalytic enantioselective construction of Si-stereocenters: recent advances and perspectives.

Silicon-stereogenic chiral organosilanes have found increasing applications in synthetic chemistry, medicinal chemistry, and materials science. In this context, various asymmetric catalytic methods have been established for the diverse synthesis of silicon-stereogenic silanes. In particular, asymmetric organocatalysis is emerging as an important and complementary synthetic tool for the enantioselective construction of silicon-stereocenters, along with the rapid development of chiral-metal catalyzed protocols. Its advent provides a powerful platform to achieve functionalized silicon-stereogenic organosilanes with structural diversity, and should lead to great development in chiral organosilicon chemistry. In this Tutorial Review, we highlight these latest achievements from two aspects: desymmetrizations of prochiral tetraorganosilanes and dynamic kinetic asymmetric transformations of racemic organosilanes by employing five organocatalytic activation modes. The advantages, limitations and synthetic value of each protocol, as well as the synthetic opportunities still open for further exploration, are also discussed.

H-Bond Donor-Directed Switch of Diastereoselectivity in the Enantioselective Intramolecular Aza-Henry Reaction of Ketimines.

We report an H-bond donor controlled diastereoselective switchable intramolecular aza-Henry reaction of ketimines derived from α-ketoesters and 2-(2-nitroethyl)anilines, allowing facile access to chiral tetrahydroquinolines bearing an aza-quaternary carbon stereocenter, which are privileged scaffold for medicinal researches. While newly developed cinchona alkaloid derived phosphoramide-bearing quaternary ammonium salt C2 selectively give cis-adducts in up to 20:1 dr and 99% ee, the corresponding urea-bearing analogue C8 preferentially give trans-adducts in up to 20:1 dr and 99% ee.

Modulating the affinity and signaling bias of cannabinoid receptor 1 antagonists.

Cannabinoid receptor 1 (CB1) is a G protein-coupled receptor and a therapeutic target for metabolic disorders. Numerous CB1 antagonists have been developed, but their functional selectivities and bias towards G protein or ß-arrestin signaling have not been systemically characterized. In this study, we analyzed the binding affinities and downstream signaling of two series of pyrazole derivatives bearing 1-aminopiperidine (Series I) or 4-aminothiomorpholine 1,1-dioxide (Series II) moieties, as well as the well-known CB1 antagonists rimonabant and taranabant. Analyses of the results for the Series I and II derivatives showed that minor structure modifications to their functional groups and especially the incorporation of 1-aminopiperidine or 4-aminothiomorpholine 1,1-dioxide motifs can profoundly affect their bias toward G protein or ß-arrestin signaling, and that their binding affinity and functional activity can be disassociated. Docking and molecular dynamics simulations revealed that the binding modes of Series I and II antagonists differed primarily in that Series I antagonists formed an additional hydrogen bond with the receptor, whereas those in Series II formed a water bridge.

Gene cloning and molecular characterization of a thermostable chitosanase from Bacillus cereus TY24.

BACKGROUND: An important conceptual advance in health and the environment has been recognized that enzymes play a key role in the green processing industries. Of particular interest, chitosanase is beneficial for recycling the chitosan resource and producing chitosan oligosaccharides. Also, chitosan gene expression and molecular characterization will promote understanding of the biological function of bacterial chitosanase as well as explore chitosanase for utilizing chitosan resources. RESULTS: A chitosanase-producing bacterium TY24 was isolated and identified as Bacillus cereus. Moreover, the chitosanase gene was cloned and expressed in Escherichia coli. Sequence analysis reveals that the recombinant chitosanase (CHOE) belongs to the glycoside hydrolases 8 family. The purified CHOE has a molecular weight of about 48 kDa and the specific activity of 1150 U/mg. The optimal pH and temperature of CHOE were 5.5 and 65 °C, respectively. The enzyme was observed stable at the pH range of 4.5-7.5 and the temperature range of 30-65 °C. Especially, the half-life of CHOE at 65 °C was 161 min. Additionally, the activity of CHOE was remarkably enhanced in the presence of Mn2+, Cu2+, Mg2+ and K+, beside Ca2+ at 5 mM. Especially, the activity of CHOE was enhanced to more than 120% in the presence of 1% of various surfactants. CHOE exhibited the highest substrate specificity toward colloid chitosan. CONCLUSION: A bacterial chitosanase was cloned from B. cereus and successfully expressed in E. coli (BL21) DE3. The recombinant enzyme displayed good stability under acid pH and high-temperature conditions.

Production of surfactant-stable keratinase from Bacillus cereus YQ15 and its application as detergent additive.

BACKGROUND: With the growing concern for the environment, there are trends that bio-utilization of keratinous waste by keratinases could ease the heavy burden of keratinous waste from the poultry processing and leather industry. Especially surfactant-stable keratinases are beneficial for the detergent industry. Therefore, the production of keratinase by Bacillus cereus YQ15 was improved; the characterization and use of keratinase in detergent were also studied. RESULTS: A novel alkaline keratinase-producing bacterium YQ15 was isolated from feather keratin-rich soil and was identified as Bacillus cereus. Based on the improvement of medium components and culture conditions, the maximum keratinase activity (925 U/mL) was obtained after 36 h of cultivation under conditions of 35 °C and 160 rpm. Moreover, it was observed that the optimal reacting temperature and pH of the keratinase are 60 °C and 10.0, respectively; the activity was severely inhibited by PMSF and EDTA. On the contrary, the keratinase showed remarkable stability in the existence of the various surfactants, including SDS, Tween 20, Tween 60, Tween 80, and Triton X-100. Especially, 5% of Tween 20 and Tween 60 increased the activity by 100% and 60%, respectively. Furtherly, the keratinase revealed high efficiency in removing blood stains. CONCLUSION: The excellent compatibility with commercial detergents and the high washing efficiency of removing blood stains suggested its suitability for potential application as a bio-detergent additive.

Changes in Gel Characteristics, Rheological Properties, and Water Migration of PSE Meat Myofibrillar Proteins with Different Amounts of Sodium Bicarbonate.

The changes in the gel and rheological properties and water-holding capacity of PSE meat myofibrillar proteins with different amounts of sodium bicarbonate (SC, 0−0.6/100 g) were studied. Compared to the PSE meat myofibrillar proteins with 0/100 g SC, the texture properties and cooking yield significantly increased (p < 0.05) with increasing SC; meanwhile, adding SC caused the gel color to darken. All samples had similar curves with three phases, and the storage modulus (G') values significantly increased with the increasing SC. The thermal stability of the PSE meat myofibrillar proteins was enhanced, and the G' value at 80 °C increased with the increasing SC. Because water was bound more tightly to the protein matrix, the initial relaxation times of T21 and T22 shortened, the peak ratio of P21 significantly increased (p < 0.05), and the P22 significantly decreased (p < 0.05), which implied that the mobility of the water was reduced. Overall, SC could improve the thermal stability of the PSE meat myofibrillar proteins and increase the water-holding capacity and textural properties of the cooked PSE meat myofibrillar protein gels.

The inhibitory effect of human DEFA5 in growth of gastric cancer by targeting BMI1.

Defensins, a class of small cysteine-rich cationic polypeptides across cellular life, are identified as antimicrobial compounds that display direct antimicrobial and immune signaling activities that are involved in the host defense. In addition to their roles in the innate immune system, accumulating studies have reported that some members of defensins are expressed and involved in some cancer cells, such as colon cancer, colorectal cancer, lung cancer and renal cell carcinomas. However, the roles of α-Defensin 5 (DEFA5) in tumorigenesis and development remain unknown. In the present study, bioinformatics analysis and quantitative PCR results showed that the expression level of DEFA5 was dramatically downregulated in human gastric cancer. Overexpression of human DEFA5 in gastric cancer cell lines SGC7901 and BGC823 effectively diminished cell proliferation and reduced the colony forming ability. Moreover, DEFA5 overexpression induced cell cycle arrest by significantly increasing the number of G1-phase cells. Consistently, in vivo tumor formation experiments in nude mice showed the suppression of the tumor growth by DEFA5 overexpression, suggesting an inhibitory effect of DEFA5 in gastric cancer. Mechanistically, DEFA5 directly binds to BMI1, which subsequently decreased its binding at the CDKN2a locus and upregulated the expression of 2 cyclin-dependent kinase inhibitors, p16 and p19. Taken together, we concluded that DEFA5 showed an inhibitory effect in gastric cancer cell growth and may serve as a potential tumor suppressor in gastric cancer.

Titanium Nanopillar Arrays Functioning as Electron Transporting Layers for Efficient, Anti-Aging Perovskite Solar Cells.

Electron transporting layers (ETLs), required to be optically transparent in perovskite solar cells (PSCs) having regular structures, possess a determinant effect on electron extraction and collection. Metal oxides (e.g., TiO2 ) have overwhelmingly served as ETLs, but usually have low electron mobility (µe  < 10-2  cm2 V-1 s-1 ) not favorable for photovoltaic conversion. Here, metal oxides are replaced with metals (e.g., Ti with µe  ≈ 294 cm2 V-1 s-1 ) that are sculptured via glancing angle deposition to be a close-packed nanopillar array (NaPA), which vertically protrudes on a transparent electrode to obtain sufficient optical transmission for light harvesting in perovskite. Ti NaPAs, whose rough surfaces are passivated with 5 nm thick TiO2 (i.e., Ti NaPAs@TiO2 ) to suppress exciton recombination, lead to the champion power conversion efficiency (PCE) of 18.89% that is superior to that of MAPbI3 PSCs without Ti NaPAs@TiO2 or containing TiO2 NaPAs@TiO2 , owing to high surface wettability, high µe , and relatively low work function of Ti. Furthermore, Ti NaPAs@TiO2 effectively prevents the decomposition of MAPbI3 to achieve long-term shelf stability whereby 50-day aging only causes 15% PCE degradation. This work paves the way toward widening the material spectrum, from semiconductors to metals, to generate a diverse range of ETLs for producing efficient optoelectronic devices with long-term shelf stability.

The non-canonical functions of telomerase reverse transcriptase gene GlTert on regulating fungal growth, oxidative stress, and ganoderic acid biosynthesis in Ganoderma lucidum.

The telomerase reverse transcriptase (TERT) is the core catalytic subunit of telomerase. Its canonical function is synthesizing telomeric repeats to maintain telomere length and chromosomal stability. Accumulating evidence suggests that TERT has other important fundamental functions in addition to its catalytic telomere repeat synthesis activity. However, the non-canonical roles of TERT independent of its enzymatic activity are not clear in filamentous fungi. In the present study, we characterized the GlTert gene in Ganoderma lucidum. The non-canonical roles of GlTert were explored using GlTert-silenced strains (Terti8 and Terti25) obtained by RNA interference. Silencing GlTert delayed the fungal growth, decreased the length between hyphal branches, and induced fungal resistance to oxidative stress in G. ludicum. Further examination revealed that the intracellular ROS (reactive oxygen species) levels were increased while the enzyme activities of the antioxidant systems (superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase) were decreased in GlTert-silenced strains. In addition, silencing GlTert decreased the ganoderic acid (GA) biosynthesis of G. lucidum. Taken together, our results indicate that GlTert plays a fundamental function on fungal growth, oxidative stress, and GA biosynthesis in G. lucidum, providing new insights for the canonical functions of TERT in filamentous fungi. KEY POINTS: • GlTert affected fungal growth and hyphal branching of G. lucidum. • Silencing GlTert increased the intracellular ROS levels of G. lucidum. • GlTert regulated GA biosynthesis of G. lucidum.

Recycling of electrode materials from spent lithium-ion power batteries via thermal and mechanical treatments.

This study developed a physical separation process that recovers active cathode materials from current collectors in spent lithium-ion power batteries (LIBs). The physical separation process, implemented via thermal and mechanical treatments, was examined based on cohesive zone models (CZMs) and verified by physical separation experiments. The most efficient condition was determined by optimising the key parameters (temperature and time) of selective heating. Among several mechanical separation methods, high-speed shearing best separates positive electrode materials into active cathode materials (LiFePO4) and current collectors (Al fragments). The separation effect was verified by computing the dissociation rate and microscopic observation of the separated materials. The feasibility and efficiency of the above process were assessed in a work-of-force analysis, flow field simulation, high-speed crushing experiment and material property analysis. The above analyses realised a feasible, efficient and environmentally friendly separation route without changing the chemical structure and properties of the electrode materials. Under non-high (energy-conserving) temperature conditions, the LiFePO4 dissociation rate stabilises at 80-85%. Under high-speed crushing, the LiFePO4 dissociation rate reaches 85% at 32,000-r/min crushing and a maximum shearing velocity of the blade edge v ≈ 500 m/s. This approach can effectively recycle electrode materials, gain valuable resources and can be used to recycle and utilise spent LIBs, thus addressing two grave issues - environmental pollution and resource wastage to achieve the sustainable development of LIBs and electric vehicle industry.

Effects of steroidal saponins extract from Ophiopogon japonicus root ameliorates doxorubicin-induced chronic heart failure by inhibiting oxidative stress and inflammatory response.

CONTEXT: Ophiopogonis Radix, the root of Ophiopogon japonicus (Thunb.) Ker-Gawl (Liliaceae), is a Traditional Chinese Medicine, which has been investigated to possess effective treatment of cardiovascular diseases. OBJECTIVE: This study evaluates the cardioprotective effects of steroidal saponins extract from Ophiopogon japonicus (SOJ) root against doxorubicin-induced chronic heart failure (CHF) through the amelioration of oxidative stress and inflammation. MATERIALS AND METHODS: A Sprague-Dawley rat model of CHF was established by intraperitoneally injected with DOX. All rats were randomly divided into four groups: Control group, CHF group, CHF + SOJ (100 mg/kg) treatment group, SOJ (100 mg/kg) treatment group (n = 8/group). After six weeks administration, biometric and echocardiography were measured. The levels of biochemical parameters were measured using commercial kits. RESULTS: The values of LVESP, +dP/dtmax, -dP/dtmax, EF and FS increased to 116.20 ± 1.68 mmHg, 2978.71 ± 168.26 mmHg/s, 3452.61 ± 286.09 mmHg/s, 68.26 ± 5.28% and 31.97 ± 3.79%, respectively; the values of LVEDP, LVESD and LVEDD decreased to 8.85 ± 0.84 mmHg, 8.39 ± 0.45 mm and 12.36 ± 0.87 mm in CHF + SOJ group. In addition, the levels of IL-6, TNF-α and IL-1ß decreased to 154.41 ± 7.72 pg/mg protein, 110.02 ± 6.96 pg/mg protein and 39.39 ± 5.27 pg/mg protein, respectively; the relative activity of p38 MAPK decreased to 2.60 ± 0.40 in CHF + SOJ group. Furthermore, the activities of SOD, CAT and GSH-Px increased to 268.77 ± 6.20 U/mg protein, 13.68 ± 0.68 U/mg protein and 316.90 ± 8.08 µmol/mg protein, and the content of MDA decreased to 4.03 ± 0.43 nmol/mg protein in CHF + SOJ group. CONCLUSIONS: SOJ exerts the cardioprotective effect against DOX-induced CHF through suppressing inflammatory and oxidative stress. These results provide evidence that SOJ might be an effective treatment for CHF.

Eddy current separation for recovering aluminium and lithium-iron phosphate components of spent lithium-iron phosphate batteries.

With the rapid development of the electric vehicle market since 2012, lithium-iron phosphate (LFP) batteries face retirement intensively. Numerous LFP batteries have been generated given their short service life. Thus, recycling spent LFP batteries is crucial. However, published information on the recovery technology of spent LFP batteries is minimal. Traditional separators and separation theories of recovering technologies were unsuitable for guiding the separation process of recovering metals from spent LFP batteries. The separation rate of the current method for recovering spent LFP batteries was rather low. Furthermore, some wastewater was produced. In this study, spent LFP batteries were dismantled into individual parts of aluminium shells, cathode slices, polymer diaphragms and anode slices. The anode pieces were scraped to separate copper foil and anode powder. The cathode pieces were thermally treated to reduce adhesion between the cathode powder and the aluminium foil. The dissociation rate of the cathode slices reached 100% after crushing when the temperature and time reached 300℃ and 120 min, respectively. Eddy current separation was performed to separate nonferrous metals (aluminium) from aluminium and LFP mixture. The optimized operation parameters for the eddy current separation were feeding speed of 1 m/s and magnetic field rotation speed of 4 m/s. The separation rate of the eddy current separation reached 100%. Mass balance of the recovered materials was conducted. Results showed that the recovery rate of spent LFP can reach 92.52%. This study established a green and full material recovery process for spent LFP batteries.

Design of a graphene-based dual-slot hybrid plasmonic electro-absorption modulator with high-modulation efficiency and broad optical bandwidth for on-chip communication.

The hybrid plasmonic effect with lower loss and comparable light confinement than surface plasmon polariton opens new avenues for strengthening light-matter interactions with low loss. Here, we propose and numerically analyze a graphene-based electro-absorption modulator (EAM) with high-modulation efficiency and broad optical bandwidth using a dual-slot hybrid plasmonic waveguide (HPW), which consists of a central dual-slot HPW connected with two taper transitions and two additional dual-slot HPWs for coupling it with the input and output silicon nanowires, where graphene layers are located at the bottom and top side of the whole dual-slot HPW region. By combining the huge light enhancement effect of the dual-slot HPW and graphene's tunable conductivity, we obtain a high-modulation efficiency (ME) of 1.76 dB/µm for the graphene-based dual-slot HPW (higher ME of 2.19 dB/µm can also be obtained). Based upon this promising result, we further design a graphene-based hybrid plasmonic EAM, achieving a modulation depth (MD) of 15.95 dB and insertion loss of 1.89 dB @1.55 µm, respectively, in a total length of only 10 µm, where its bandwidth can reach over 500 nm for keeping MD>15 dB; MD can also be improved by slightly increasing the device length or shrinking the waveguide thickness, showing strong advantages for applying it into on-chip high-performance silicon modulators.

Volatile Composition in Two Pummelo Cultivars (Citrus grandis L. Osbeck) from Different Cultivation Regions in China.

This study investigated the composition of volatile compounds in two pummelo cultivars, including 'Shatian' and 'Guanxi', cultivated in different regions of China with the aim of studying the effect of cultivar and cultivation condition on biosynthesis of volatile compounds in pummelo. Volatile compounds were extracted from pummelo juice using head-space microextraction and then analyzed using gas chromatography coupled with mass spectrometry. Results showed that a total of 49 volatile compounds was detected in the study, including 11 aldehydes, 7 alcohols, 3 ketones, 7 esters, 19 terpenes and 2 other volatiles. The 'Guanxi' pummelo cultivar possessed a more complex composition of volatile compounds compared with the 'Shatian' cultivar. Meanwhile, the volatile compounds appeared to exhibit a higher concentration in the 'Guanxi' cultivar samples than the 'Shatian' cultivar. Cluster analysis revealed that the 'Guanxi' cultivar samples from the different regions were grouped together, whereas the 'Shatian' cultivar samples were assembled. Principal component analysis showed that an obvious separation was observed between the 'Guanxi' and 'Shatian' cultivar. However, the 'Shatian-SC15' was significantly separated from the other 'Shatian' cultivar samples. These indicated that cultivar genotype was the primary factor that determined the volatile profile of the pummelo cultivar. Cultivation region might affect the biosynthesis of volatile compounds, resulting in the differentiation of the volatile composition in each pummelo cultivar.

[In Situ Analysis of Element Geochemistry in Submarine Basalt in Hydrothermal Areas from Ultraslow Spreading Southwest Indian Ridge].

In this study, we analyze element geochemistry of submarine basalt in situ, which is sampled in hydrothermal areas from ultraslow spreading Southwest Indian Ridge, including the fresh basalt rocks (B19-9, B15-13) and altered basalt (B5-2). And we can confirm that altered mineral in B5-2 is celadonite by microscope and Raman Spectrum. Furthermore, amygdaloidal celadonites are analyzed by electron microprobe (EPMA) and EDS-line scanning. The results show that K-contents decrease and Na-contents increase from the core to the edge in these altered minerals, indicating the transition from celadonite to saponite. Celadonite is an altered minerals, forming in low temperature (< 50 degrees C) and oxidizing condition, while saponite form in low water/rock and more reducing condition. As a result, the transition from celadonite to saponite suggests environment change from oxidizing to reducing condition. Using the result of EPMA as internal standard, we can analyze rare earth elements (REE) in altered mineral in situ. Most of result show positive Eu anomaly (Δ(Eu)), indicating hydrothermal fluid transform from oxidizing to reducing, and reducing fluid rework on the early altered minerals. Comparison with REE in matrix feldspar both in altered and unaltered zoning, we find that reducing fluid can leach REE from the matrix feldspar, leading to lower total REE concentrations and positive Eu anomaly. So leaching process play an important role in hydrothermal system.

Study on biodegradability of terephthalic acid in polyester fabric alkali-peeling process wastewater.

Terephthalic acid (TA) and ethylene glycol (EG) are the main pollutants in polyester fabric alkali-peeling process wastewater (PAP-wastewater). The biodegradability of TA is crucial to the deep treatment of PAP-wastewater. Batch and continuous experiments were adopted to study the biodegradation of TA in synthetic wastewater. In anoxic batch experiments TA began to degrade gradually after EG was depleted completely. However, in aerobic batch experiments the biodegradation curves of TA in the presence of EG were almost identical to those of TA in the absence of EG. The combined process of anoxic hydrolysis-acidification bioreactor (HABR) and aerobic hybrid membrane bioreactor (HMBR) was employed to treat synthetic PAP-wastewater in continuous experiments. When TA was fed as sole substrate, about 6.1% was removed in the anoxic HABR and 92.1% was biodegraded in the aerobic HMBR. When TA and EG were fed as substrate, only 1.9% of TA was biodegraded in the anoxic HABR and 96.6% of TA was removed in the aerobic HMBR. By contrast, most EG was removed in the anoxic HABR. The experimental results revealed that the combined process of anoxic HABR and aerobic HMBR was an attractive alternative for the treatment of PAP-wastewater and other similar wastewater.

[The enrichment characteristic and mechanism of gold-silver minerals in submarine hydrothermal sulfides from the ultra-slow-spreading SWIR].

In the present study, content and occurrence of Au, Ag in three submarine hydrothermal sulfide samples from the ultra-slow-spreading Southwest Indian Ridge (SWIR) were studied by using inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results of ICP-AES show that all of the samples have signs of Au-Ag enrichment. By SEM/EDS, we discovered a mass of gold-silver minerals in the samples. In S27-4, gold occurs as irregular-shaped native gold and electrum grains in sulfides or between crystal particles. However, we discovered lots of Au-independent silver minerals except parts of electrum in S35-22. EDS results of silver minerals indicate that silver minerals closely related with halogen element, inferring that silver minerals may be silver halides. Electrum in S35-22 can be absorbed at the surface or crystal edge of pyrite besides occurring in or between sulfides as S27-4, supposed to be related to surface defect in pyrite. Electrum is the only Au-Ag mineral discovered in S35-17. These electrum gains occur as inclusion gold, absorbed gold or fissure gold. In addition, there are different Au-Ag mole ratios of electrum in three samples, indicating distinct hydrothermal conditions. In the base of research before, we consider that AgCl2(-) is the dominant complex of silver in ore-forming fluid of S27-4, however, gold is transported as AuCl2(-) transforming to AuHS(0), indicating that hydrothermal fluids decreased from high-moderate to moderate-low temperature and conductive cooling played an important role in this process. Similar enrichment mechanism happened in S35-22, but silver halides discovered in S35-22 suggest a higher temperature and chloride in the early stage. However, The enrichment of electrums in black smoke sample (S35-17) relates to mixing of hydrothermal fluids and seawater.

[Retracted] LncRNA TUG1 serves an important role in hypoxia­induced myocardial cell injury by regulating the miR­145­5p­Binp3 axis.

Following the publication of this article, a concerned reader drew to the Editor's attention that, for several of the figures showing the results of Transwell migration and invasion assay experiments, unexpected areas of similarity were identified in terms of cellular patterns comparing among data panels where the results from differently performed experiments were intended to have been shown, although the areas immediately surrounding these areas often featured comparatively different distributions of cells. Moreover, several of the figures contained invasion/migration assay data that were strikingly similar to data that had appeared in articles published previously by different authors at different research institutes. In addition, the western blots in this article were presented with atypical, unusually shaped and possibly anomalous protein bands in many cases. After having conducted an internal investigation, the Editor of Molecular Medicine Reports has reached the conclusion that the potentially anomalous data in this paper were unlikely to have arisen by coincidence. Therefore, on the grounds of a lack of confidence in the integrity of these data, and given the fact that some of the data were strikingly similar to that which had been published previously in other articles and journals, the Editor has decided that the article should be retracted from the publication. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused, and thanks the concerned reader for drawing this matter to our attention. [Molecular Medicine Reports 42: 2422­2430, 2018; DOI: 10.3892/mmr.2017.8116].

Characteristics of exopolysaccharides from Paecilomyces hepiali and their simulated digestion and fermentation in vitro by human intestinal microbiota.

The metabolic process of polysaccharides in gastrointestinal digestions and the effects of the resulting carbohydrates on the composition of gut microbes are important to explore their prebiotic properties. Therefore, the purpose of this study was to investigate the simulated digestion and fecal fermentation in vitro of three fractions (PHEPSs-1, PHEPSs-2 and PHEPSs-3) purified from the crude exopolysaccharides of Paecilomyces hepiali HN1 (PHEPSs) and to explore the potential prebiotic mechanisms. The three purified fractions were characterized by HPLC, UV, FT-IR, SEM and AFM, and they were all of galactoglucomannan family with molecular weight of 178, 232 and 119 kDa, respectively. They could resist the simulated gastrointestinal digestions, but they were metabolized in fecal fermentation in vitro. Furthermore, the mannose in PHEPSs showed a higher utilization rate than that of glucose or galactose. The proliferation effects of PHEPSs on Bifidobacterium and Lactobacillus were weaker significantly than those of fructooligosaccharides before 12 h of fecal fermentation, but stronger after 24 h of fecal fermentation. Meanwhile, higher levels of short-chain fatty acids were found in PHEPSs groups when the fecal fermentation extended to 36 h. Therefore, PHEPSs are expected to have a potent gut healthy activity and can be explored as functional food ingredients.

Using ultrasonic-assisted sodium bicarbonate treatment to improve the gel and rheological properties of reduced-salt pork myofibrillar protein.

To study the impact of ultrasonic duration (0, 30, and 60 min) and sodium bicarbonate concentration (0% and 0.2%) on the gel properties of reduced-salt pork myofibrillar protein, the changes in cooking yield, colour, water retention, texture properties, and dynamic rheology were investigated. The findings revealed that added sodium bicarbonate significantly increased (P < 0.05) cooking yield, hardness, springiness, and strength of myofibrillar protein while reducing centrifugal loss. Furthermore, the incorporation of sodium bicarbonate led to a significant decrease in L⁎, a⁎, b⁎, and white values of cooked myofibrillar protein; these effects were further amplified with increasing ultrasonic duration (P < 0.05). Additionally, storage modulus (G') significantly increased for myofibrillar protein treated with ultrasonic-assisted sodium bicarbonate treatment resulting in a more compact gel structure post-cooking. In summary, the results demonstrated that ultrasonic-assisted sodium bicarbonate treatment could enhance the tightness of reduced-salt myofibrillar protein gel structure while improving the water retention and texture properties.