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Selective functionalization of C–F bonds in trifluoromethyl groups has recently received a growing interest, as it offers atom- and step-economic pathways to access highly valuable mono- and difluoroalkyl-substituted organic molecules using simple and inexpensive trifluoromethyl sources as the starting materials. In this regard, impressive progress has been made on the defluorinative functionalization reactions that proceed via radical intermediates. Nevertheless, it is still a great challenge to precisely control the defluorination process, due to the continuous decrease of the C–F bond strength after the replacement of one or two fluorine atoms with various functionalities. This review article is aimed to provide a brief overview of recently reported methods used to functionalize C–F bonds of CF3 groups via radical intermediates. An emphasis is placed on the discussion of mechanistic aspects and synthetic applications

Sequentially snipping off fluorines It is often useful in pharmaceutical or agrochemical research to modify the properties of carbon compounds by appending one or more fluorine atoms. However, the methods used to prepare mono-, di-, or trifluorocarbon centers tend to differ from each other in inconvenient ways. Yu et al. developed a radical reaction that can successively remove one or two fluorine atoms from trifluoromethyl groups adjacent to amides or esters. The mechanism relies on a spin-center shift after attack at the carbonyl oxygen by a boryl radical. Science , this issue p. 1232

The relationships between chemical composition, structure and physicochemical properties such as pasting, thermal, and textural properties of 12 temperate rice cultivars grown in Heilongjiang Province, China were investigated in this study. There were significant differences in the content of fat, protein, ash, amylose, damaged starch among 12 cultivars. Brabender Viscograph results showed that gelatinization time, peak viscosity, pasting and peak temperature ranged from 9 min to 15 min, 2100 BU to 2500 BU, 58.75 ℃ to 72.00 ℃ and 63.75 ℃ to 84.45 ℃, respectively, except for the waxy one Longjing 9. To, Tp, Tc and ΔH were found in the range of 58.34 ℃ to 67.96 ℃, 65.39 ℃ to 75.38 ℃, 78.47 ℃ to 90.69 ℃ and 2.036 J/g to 3.127 J/g respectively. Scanning Electron Micro-photograph results showed that all starch granules were polyhedral with irregular shapes, except Longjing 9 showing signs of the loss of physical integrity. The hardness, adhesiveness, springiness, gumminess, cohesiveness and resilience ranged from 395.87 g to 1161.76 g, -90.842 g·mm to -36.4 g·mm, 0.498 to 0.747, 78.631 g to 466.837 g, 0.199 to 0.569, 0.321 to 0.504, respectively. Correlation studies indicated that amylose, damaged starch, protein, fat and ash played a more important role in determining the rice properties of pasting, thermal, crystallinity and texture.

Unprecedented palladium-catalysed regio- and stereo-selective coupling reactions of homoallenylboronates with (hetero)aryl iodides, allyl bromides and alkynyl bromides in aqueous solution were successfully developed. The corresponding 1,3-dienes, skipped dienes and conjugate enynes were obtained as products, respectively, in high yields and with specific stereoselectivity. Therefore, the homoallenylboronates were potentially powerful and flexible “platform” molecules to form the complex 1,3-dienyl compounds.

The environmental pollution, evolution of resistance, and risks to human and aquatic animal health associated with pesticide application have attracted much attention globally. Herein, we tested the capacity of diallyl trisulfide (DAT) from garlic essential oil to control the destructive stored-product pest, Sitotroga cerealella. The effects of DAT on the total content of cuticular chitin and structure of adults S. cerealella were evaluated. This study was the first to investigate changes in chitin structure in adults due to exposure to DAT through Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, and differential scanning calorimetry. The results of these analyses revealed that the cuticular chitin content of pests decreased after DAT treatment. DAT treatment also reduced thermal stability and crystallinity of chitin. These findings indicate that DAT is a potent biopesticide that is active against the moth, and establishes the basis for its use as an IPM and alternative to chitin synthesis inhibitors.

A copper-catalyzed anti-Markovnikov hydrosilylation of alkynes with PhSiH3 was reported. This reaction represents a notable and efficient example on copper-catalyzed hydrosilylatioin of alkynes, which shows excellent recognition between the terminal and internal triple bonds. Various (hetero)aromatic and aliphatic substituted terminal alkynes underwent this reaction to afford the (E)-vinylsilanes in high yields and with excellent regioselectivity.

An electrooxidative [3 + 2] annulation of phenols and electron-deficient alkenes for the synthesis of C3-functionalized 2-aryl-2,3-dihydrobenzofuran derivatives was achieved. The ring construction starts by a unique α-addition of carbon radicals derived from anodic oxidation of phenols to electron-deficient alkenes. The subsequent anodic oxidation of the resulting alkyl radical intermediates followed by trapping with the phenolic hydroxy group assembles the 2,3-dihydrobenzofuran core. Such a pathway enables the installation of various electrophilic functionalities including alkoxycarbonyl, alkylaminocarbonyl, trifluoromethyl, and cyano groups at the C-3 of the 2,3-dihydrobenzofuran framework, which is unattainable by other intermolecular reactions. The application of this method for a rapid synthesis of a bioactive natural product is demonstrated., An electrooxidative [3 + 2] annulation between phenols and electron-deficient alkenes for the synthesis of C3-functionalized 2-aryl-2,3-dihydrobenzofuran derivatives is described.

Our present study unveils a new and efficient N-heterocyclic carbene (NHC)-boryl radical-catalyzed cycloisomerization of N-(2-ethynylaryl)arylamides. This catalytic process is triggered by the addi...

A regioselective radical hydroboration of gem-difluoroalkenes was developed for the synthesis of α-difluoroalkylborons. The reaction features excellent regioselectivity, broad substrate scope, and good functional group capability. DFT calculations implicated the remarkable α-selectivity was driven from the kinetically and thermodynamically more favorable α-addition step. The resulting α-difluoroalkylborons could be readily converted into NHC-borane-tethered monofluoroalkenes, which demonstrated unique reactivity and applicability in the synthesis of monofluoroalkene derivatives through transformations of the boron unit.

Transparent e-skin that can fully mimic human skin with J-shaped mechanical-behavior and tactile sensing attributes have not yet been reported. In this work, the skin-like hydrogel composite with J-shaped mechanical behavior and highly transparent, tactile, soft but strong, flexible, and stretchable attributes is developed as structural strain sensing element for e-skin. Piezo-resistive polyacrylamide (PAAm) hydrogel is used as supporting matrix to endow high transparency, softness, flexibility, stretch-ability and strain sensing capability desired for e-skin. Ultrahigh molecular weight polyethylene (UHMWPE) fiber with a wavy configuration is designed as reinforcement filler to provide the tunable strain-limiting effect. As a result, the as-prepared UHMWPE fiber/PAAm composite e-skin presents unique "J-shape" stress-strain behavior akin to human skin. And the PAAm composite can switch from supersoft to highly stiff in the designed strain range up to 100% with a prominent tensile strength of 48.3 MPa, which enables it to have the high stretch-ability and excellent load-bearing ability, simultaneously. Moreover, finite element model is developed to clarify the stress distribution and damage evolution for the UHMWPE fiber/PAAm composite during the tensile process. The PAAm composite exhibits not only an excellent strain sensing performance with a long-term reliability up to 5000 loading-unloading cycles but also an extraordinary softness and mechanical strength with a low initial modulus of 6.7 kPa, which is matchable with soft human epidermis. Finally, the e-skin is used for demonstrations in monitoring various human activities and protecting structural integrity in designed strain ranges. The strategy for reinforcing piezo-resistive hydrogel with wavy-shaped UHMWPE fibers proposed here is promising for the development of transparent, flexible, soft but strong e-skin with a tunable strain-limiting effect akin to human skin.

In this study, reaction of 2-(5-(pyridin-3-yl)-4-(pyridin-4-yl)-4H-1,2,4-triazol-3-yl)pyridine (L) with Ni(NO3)2·6H2O or CuBr2 leads to the formation of two discrete coordination complexes [Ni(L)2(H2O)2](NO3)2 (1) and [Cu(L)Br2](H2O)(DMF)2 (2) with different metal cluster composing. Various structural characterization methods such as thermogravimetric analysis (TGA), elemental analysis (EA), powder as well as single crystal X-ray diffraction measurements were used to study the compositions along with the atom arrangement of the two as-prepared coordination complexes. Furthermore, the grinding method was used to downsize the crystal size of the complexes 1 and 2 into nano region to make them useable. In connection to these, the anticancer activities of the as-prepared two complexes have been studied via access the cell validity and the IC50 values of three human osteogenic sarcoma cells (MG-63, U2SO and Saos-2).

The development of a process that could recover biofuel from industrial cellulose waste can not only reduce the negative environmental impacts by using fossil fuels, but also bring a green idea for the waste's disposing. In this study, hydrothermal pretreatment was optimized for cassava anaerobic residue, a cellulosic waste from cassava ethanol industry, to co-utilize xylose and glucose for producing bioethanol. The effect of the main pretreatment conditions, namely, temperature, solid content and time, was explored for the highest recovery of xylose in prehydrolysate and glucose in enzymatic hydrolysate. The single factor experiment results showed that the conditions for maximum xylose recovery in prehydrolysate and glucose recovery in enzymatic hydrolysate were 60 °C, 75 min, 10% solids and 160 °C, 75 min, 10% solids, respectively. Whereafter, response surface methodology (RSM) was applied to further optimize the pretreatment conditions for the maximum theoretical ethanol production through utilizing both xylose and glucose. A treatment at 163 °C, for 59 min and with 9.5% solids was found optimal, with the highest ethanol production of 20.2 mg·g−1 raw material. Furthermore, in order to assess the impacts of the pretreatment on cassava anaerobic residue, the changes in crystallinity and morphology for untreated and pretreated solids were investigated.

Organoboron compounds are highly valuable in synthetic chemistry. In particular, α-borylcarbonyl compounds have shown versatile synthetic applications, owing to fruitful chemistries of both the boryl and carbonyl moieties. However, the synthesis of these molecules still remains tedious and time-consuming. Here we report a straightforward and practical route to synthesize α-borylcarbonyl molecules based on a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds. The reaction features unusual α-regioselectivity and high functional-group compatibility. Further synthetic applications of new α-borylated products were also demonstrated. DFT and kinetic studies implicated that the α-regioselectivity of β-aryl-α,β-unsaturated carbonyl compounds was determined by the thermodynamically more favorable radical α-addition step, whereas the formation of α-addition products from β-alkyl-α,β-unsaturated carbonyl compounds was driven by an energetically favored hydrogen atom transfer step. Given that α,β-unsaturated carbonyl compounds can be easily obtained in abundance and variety, this method enjoys great advantages in diverse and economical synthesis of valuable α-borylcarbonyl molecules., α-Borylcarbonyl compounds are versatile synthons in organic synthesis, however their preparation is often tedious. Here, the authors report a regioselective radical α-borylation of α,β-unsaturated carbonyl compounds to afford α-borylcarbonyl molecules with high selectivity and functional group compatibility.

This study investigated the effects of spontaneous and Lactobacillus plantarum (LP) fermentation on structure glutinous proso millet starch (GPM) and physical properties. In order to explore starch changes by fermentation for quality regulation of fermented food glutinous proso millet and improve properties of modified GPM starch products. The molecular weight, amylopectin chain length distribution, morphological properties, short-range ordered structure, and crystal structure of GPM starch were analyzed. Results showed that compared with the non-fermented GPM starch, amylose content of spontaneous and LP-fermented GPM starch increased then decreased, with the latter decreasing faster. There were no changes in the Type A structures of spontaneous fermented, LP-fermented, and non-fermented GPM starch. After 24 h of LP fermentation, higher water swelling power, and lower GPM starch solubility were obtained compared to non-fermentation and spontaneous fermentation. The decrease in pasting properties and thermal properties while increasing GPM starch properties was shown after fermentation compared to non-fermentation experiments. Besides, LP fermentation showed faster changes of these properties than spontaneous fermentation. In conclusion, our findings showed that fermentation could improve GPM starch properties, benefiting fermented GPM products and as a modification method for GPM starch. Especially, LP fermentation was more effective than spontaneous fermentation.

An efficient direct aldol reaction between coumaran-3-ones and β, γ-unsaturated α-ketoesters by virtue of a chiral copper complex is developed. A series of coumaran-3-one derivatives containing chiral tertiary alcohol structures are obtained in excellent yields and stereoselectivities.

In this study, the mineral-weathering bacterium Pseudomonas azotoformans F77, which was isolated from the soil of a debris flow area, was evaluated for its weathering activity under direct contact with biotite or without contact. Then, biotite-weathering behaviors of strain F77, mutants that had been created by deleting the gcd and adh genes (which are involved in gluconic acid metabolism and pilus formation, respectively), and the double mutant F77ΔgcdΔadh were compared. The relative gene expression levels of F77 and its mutants F77Δgcd and F77Δadh were also analyzed in the presence of biotite. Direct contact with biotite increased Fe and Al release from the mineral in the presence of F77. All strains had similar abilities to release Fe and Al from the mineral except for F77Δgcd and F77Δadh. Mobilized Fe and Al concentrations were decreased by up to 72, 26, and 87% in the presence of F77Δgcd, F77Δadh, and F77ΔgcdΔadh, respectively, compared to levels observed in the presence of F77 during the mineral-weathering process. Gluconic acid production was decreased for F77Δgcd and F77ΔgcdΔadh, while decreased cell attachment on the mineral surface was observed for F77Δadh, compared to findings for F77. The F77 genes involved in pilus formation and gluconic acid metabolism showed increased expression levels in the presence of biotite. The results of this study showed important roles for the genes involved in gluconic acid metabolism and pilus formation in mineral weathering by F77 and demonstrated the distinctive effect of these genes on mineral weathering by F77. IMPORTANCE Bacteria play important roles in mineral weathering and soil formation, although the molecular mechanisms underlying the interactions between bacteria and silicate minerals are poorly understood. In this study, the interactions between biotite and the highly effective mineral-weathering bacterium P. azotoformans F77 were characterized. Our results showed that the genes involved in gluconic acid metabolism and pilus formation play important roles in mineral weathering by F77. The presence of biotite could promote the expression of these genes in F77, and a distinctive effect of these genes on mineral weathering by F77 was observed in this study. Our results provide new knowledge and promote better understanding regarding the interaction between silicate minerals and mineral-weathering bacteria, as well as the molecular mechanisms involved in these processes.

The variations in flavor substances across the different stages of fermented soybean whey tofu (FSWT) production were analyzed by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with principal component analysis (PCA). The results revealed 24 representative flavor compounds in the samples across all production stages. After heating, the signal intensity of hexanal, 1-octen-3-ol, heptanal, and (E)-2-hexenol, which are unpleasant flavor substances found in raw soymilk, weakened, whereas those of some aroma substances increased. Furthermore, fermented flavor compounds, namely, 2-heptanone, 2-pentylfuran, pentanal, and 2,3-butanedione, were produced after the addition of fermented soybean whey as a coagulant. A PCA based on the signal intensity of the detected volatile compounds revealed effective differentiation of samples from different stages into comparatively independent spaces. These results showed that the flavor fingerprints of the samples from different stages of FSWT production can be successfully built using HS-GC-IMS and PCA based on the detected volatile compounds.

A new and practical α-monomethylation strategy using an amine-borane/N,N-dimethylformamide (R3 N-BH3 /DMF) system as the methyl source was developed. This protocol has been found to be effective in the α-monomethylation of arylacetonitriles and arylacetamides. Mechanistic studies revealed that the formyl group of DMF delivered the carbon and one hydrogen atoms of the methyl group, and R3 N-BH3 donated the remaining two hydrogen atoms. Such a unique reaction pathway enabled controllable assemblies of CDH2 -, CD2 H-, and CD3 - units using Me2 NH-BH3 /d7 -DMF, Me3 N-BD3 /DMF and Me3 N-BD3 /d7 -DMF systems, respectively. Further application of this method to the facile synthesis of anti-inflammatory flurbiprofen and its varied deuterium-labeled derivatives was demonstrated.

Leptin is well acknowledged as an anorexigenic hormone that plays an important role in feeding control. Hypothalamic GABA system plays a significant role in leptin regulation on feeding and metabolism control. However, the pharmacological relationship of leptin and GABA receptor is still obscure. Therefore, we investigated the effect of leptin or combined with baclofen on the food intake in fasted mice. We detected the changes in hypothalamic c‐Fos expression, hypothalamic TH, POMC and GAD67 expression, plasma insulin, POMC and GABA levels to demonstrate the mechanisms. We found that leptin inhibit fasting‐induced increased food intake and activated hypothalamic neurons. The inhibitory effect on food intake induced by leptin in fasted mice can be reversed by pretreatment with baclofen. Baclofen reversed leptin's inhibition on c‐Fos expression of PAMM in fasted mice. Therefore, these results indicate that leptin might inhibit fasting‐triggered activation of PVN neurons via presynaptic GABA synaptic functions which might be partially blocked by pharmacological activating GABA‐B. Our findings identify the role of leptin in the regulation of food intake.

The Angoumois grain moth, Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), is primarily a pest of stored products, that feeds inside the grain as larvae inducing significant economic loss in various stored commodities. Our previous studies proved that garlic essential oil and its active substances inhibit oviposition in moths. To further explore the effect on reproductive behavior and accurately interpret the results in terms of effective control of the moth population, moths were treated with diallyl trisulfide (DATS), an active substance of garlic essential oil, at a dose of 0.015 µL/L in air (LC20, sub-lethal concentration). The results showed that fecundity and the proportion of viable eggs significantly decreased when the moths were treated with LC20 DATS. Furthermore, female circadian mating rhythms and calling periodicity changed significantly after treatment. Compared with controls, the peak in mating occurred approximately 1 h earlier on the first day after DATS treatment, while it was significantly later on days 2 and 3. Moreover, mating frequency declined in presence of DATS compared with the controls. The percentage of females engaging in calling behavior decreased significantly with time, to less than 50%, 2 days after treatment, while a high calling percentage (>80%) was recorded for control moths on all 4 days. In addition, DATS had an inhibitory effect on the mating duration of S. cerealella. Moreover, a significant reduction was observed in the amount of sex pheromones extracted 8 h and 9 h after treatment. Our findings suggested that DATS has the potential to manipulate the moth population at LC20 and would be an efficient alternative to synthetic insecticides for the control of pests having low toxicity to non-target organisms and ecosystems.

Radical borylation using N-heterocyclic carbene (NHC)-BH3 complexes as boryl radical precursors has emerged as an important synthetic tool for organoboron assembly. However, the majority of reported methods are limited to reaction modes involving carbo- and/or hydroboration of specific alkenes and alkynes. Moreover, the generation of NHC-boryl radicals relies principally on hydrogen atom abstraction with the aid of radical initiators. A distinct radical generation method is reported, as well as the reaction pathways of NHC-boryl radicals enabled by photoredox catalysis. NHC-boryl radicals are generated via a single-electron oxidation and subsequently undergo cross-coupling with the in-situ-generated radical anions to yield gem-difluoroallylboronates. A photoredox-catalyzed radical arylboration reaction of alkenes was achieved using cyanoarenes as arylating components from which elaborated organoborons were accessed. Mechanistic studies verified the oxidative formation of NHC-boryl radicals through a single-electron-transfer pathway.

Inhibition of bone regeneration by wear debris is the main cause of peri-prosthetic osteolysis. Here, we investigated the effect of icariin on cell proliferation, apoptosis, osteogenic differentiation and matrix mineralization of osteoblasts in an in vitro model of titanium (Ti) particle-induced osteolysis. In the present study, MC3T3-E1 cells were pretreated with 10-8 M icariin for 4 h and then incubated with Ti particles (0.1 mg/mL). The results showed that Ti particles inhibited cell proliferation and promoted cell apoptosis of MC3T3-E1 cells, whereas icariin pretreatment blocked the effect of Ti particles. In addition, we found that icariin stimulation alone increased ALP activity, accelerated matrix mineralization and upregulated the levels of bone morphogenetic protein 2 (BMP2), Runt-related transcription factor 2 (Runx2), osteocalcin (OCN) and miR-21-5p; whereas, Ti particles alone exerted the opposite effects. Icariin partly reversed the effect of Ti particles on cell differentiation and mineralization. Twenty hours after transfection with antagomiR-21-5p or antagomiR-NC, the cells were pretreated with icariin for 4 h and then incubated with Ti particles. Further studies showed that partial knockdown of miR-21-5p abolished the promotion effect of icariin on osteoblast differentiation and matrix mineralization in Ti particle-stimulated MC3T3-E1 cells. In conclusion, miR-21-5p may be a potential pro-osteogenesis regulator and icariin may protect against Ti particle-induced inhibition of osteogenic differentiation and mineralization through upregulation of miR-21-5p.

The angoumois grain moth, Sitotroga cerealella Olivier, is a serious stored-grain pest worldwide. In previous studies, we demonstrated that diallyl trisulfide (DATS), one of active substances from garlic essential oil, inhibited oviposition of S. cerealella, but the mechanism for this inhibition remains unclear. We suspected that DATS-regulated gene expression changes in S. cerealella may be a reason for the modulation of fertility and reproductive behaviors of the moth. Comparative transcriptomes of female S. cerealella were built by RNA-sequencing to detect differences between DATS exposure and background air with special lights on the key genes related to the fecundity. A total of 304 differentially expressed genes (DEGs) were detected in female moth after exposure to DATS, of which 120 were up-regulated, and 184 were down-regulated. Sixty-two of these DEGs encoding proteins involved in growth and development of eggs and regulation of hormones and mating behavior were identified, and of these, 49 were annotated as chorion protein. Meanwhile, quantitative real-time PCR verified that DEG data were reliable for further transcriptional analysis. Additionally, the results of ovarian dissection and oviposition activity bioassay suggest that DATS has negative effects on ovarian development and fecundity of S. cerealella. Our comprehensive sequence resource with desirable quality enriched the genomic platform of S. cerealella, and the DEGs that were identified will facilitate understanding of the molecular mechanism of ovipositional inhibition by DATS.

Hydrothermal reaction was first applied to pretreat cassava alcohol residue for realizing the co-utilization of xylose and glucose to assume fermentation ethanol. This work focused on the influence of hydrothermal pretreatment conditions on ethanol production. Hydrothermal reaction was used to explore the maximum xylose and glucose yields, in respect to reaction temperature (120–240 °C), solid-liquid ratio (0.023–0.150) and reaction time (15–120 min). The results showed that the suitable conditions were at 180–200 °C, for 45–60 min and with 10–12.5% solids. In this range, the conjunct of xylose and glucose would reach the maximum, which can make full use of hemicellulose and cellulose in cassava alcohol residue. According to the results, respond surface methodology (RSM) based on Box-Behnken design was used to further optimize the three independent variables for the highest ethanol by co-utilization of xylose and glucose. RSM revealed that the effect of temperature on ethanol production was much more significant than the effect of reaction time and solid-liquid ratio, and the highest ethanol production was 70.6 mg/g that was close to the experiment value of 69.5 mg/g at 193 °C for 51 min and with 11.5% solids. Furthermore, the crystallinity and morphology of the untreated and pretreated cassava alcohol residue were investigated to assess the effect of hydrothermal pretreatment by scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively.

A regioselective radical hydroboration of various electron-deficient alkenes is achieved by the employment of an NHC–boryl radical. A range of α-borylated nitriles, trifluoromethyl molecules, phosphonates, sulfones, and gem-diboron compounds have been prepared from readily available starting materials. Further synthetic applications of these products are also demonstrated.

A hydroponic study was conducted to determine the effects of selenium (Se: 0, 3, 6 μmol L –1 ) on senescence-related oxidative stress in garlic plants grown under two sulfur (S) levels. We evaluated the yields of plants harvested at 160 and 200 days after sowing. Plants grown under a low Se dose (0.3 μmol L –1 ) at low S level showed higher yields (12.0% increase in fresh weight yield, 13.7% increase in dry weight yield) than the controls, despite a decrease in chlorophyll concentration. Compared with control plants, the Se-treated plants showed lower levels of lipid peroxidation. The Se-treated plants also showed higher activities of glutathione peroxidase and catalase, but lower superoxide dismutase activities. Changes in F v / F m values and proline contents were affected more strongly by S than by Se. On the basis of our results, we can conclude that Se plays a key role in the antioxidant systems in garlic seedlings. It delays senescence by alleviating the peroxide stress, but it can be toxic at high levels. A high S level may increase tolerance to high Se concentrations through reducing Se accumulation in plants.

A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes (nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), total 1-hydroxypyrene (1-HOP) and 3-hydroxybenzo[a] pyrene (3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats’ urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group.

During the batch bioethanol fermentation process, although Saccharomyces cerevisiae cells are challenged by accumulated ethanol, our previous work showed that the ethanol tolerance of S. cerevisiae increased as fermentation time increased. However, the exact molecular mechanisms underlying the increased ethanol tolerance of S. cerevisiae are still poorly understood. In this study, a gas chromatography-mass spectrometry-based metabolomics strategy was used to determine the fermentation process-associated intracellular metabolic changes in S. cerevisiae cells. With the aid of partial least squares-discriminant analysis between two of the three fermentation stages (i.e., the lag, exponential, and stationary phases), 40 differential metabolites with variable importance and a projection value greater than 1 were identified. During the bioethanol fermentation process, S. cerevisiae cells could continuously remodel their membrane composition and structure to obtain higher ethanol tolerance. During the lag–exponential phase transition, in spite of a down-regulated TCA cycle, the increased ergosterol content combined with decreased saturated fatty acid content might be the most significant factor in making yeast cells more robust and ethanol-tolerant. During the exponential–stationary phase transition, a re-activated TCA cycle could provide plenty of energy, and the increased energy production together with the increased energy requirements might be partly responsible for the increased ethanol tolerance in the stationary phase. Moreover, the increased content of glycerol, trehalose, ergosterol and some amino acids also might jointly confer the yeast cells with higher ethanol tolerance. These results highlighted our knowledge about the relationship between the bioethanol fermentation process and ethanol tolerance, and could contribute to the construction of feasible ethanologenic strains with higher ethanol tolerance.

This study investigated the effects of diallyl trisulfide (DAT), an active substance from garlic essential oil, on the metabolism of the main energy substances of pre- and postmating males of Sitotroga cerealella. Males at 12 h postemergence were fumigated with DAT at a concentration (LC10 = 0.010 µL/L) in a glass jar for 7 h. The main energy metabolites from pre- and postmating males were determined, including protein, triglyceride, glycogen, total soluble sugar, trehalose, and trehalase. The contents of total protein and total soluble sugar and the trehalase activity of premating males were significantly increased following DAT treatment, whereas the contents of protein from the accessory gland, triglyceride, glycogen, and trehalose were significantly decreased after treatment. Additionally, after mating, the total protein and soluble sugar contents were significantly increased and the glycogen content was significantly decreased in the treatment group relative to the levels in controls, but there was no significant difference observed in triglyceride, accessory gland proteins, trehalose content, or trehalase activity between the treatment and control groups. Furthermore, the changes in the main energy substances between pre- and postmating in males after the DAT treatment (∆DAT) were smaller than those in the control group (∆CK). This result indicated that DAT can accelerate the rate of metabolism in males at LC10, leading to the accumulation of greater levels of total soluble sugar to support life activities and to the increased synthesis of proteins to resist an adverse environment.

Besides the prominent tactile sensing ability, human skin is also well known for its unique mechanical behavior – combination of excellent softness with certain stretchability of a strain-limiting effect to prevent damage from excessive strain. Here a stretchable e-skin truly mimicking the tactile sensing and mechanical behavior of human skin is fabricated. Carbon black (CB)/silicone composite with excellent piezo-resistive performance is employed as mechanical stimuli sensing material, which provides super softness, large stretchability, high strain sensitivity and long-term reliability for the e-skin. High performance carbon fiber (CF) with quasi-sinusoidal shape is designed to serve as electrode material and reinforcement filler simultaneously, which renders the e-skin a typical J-shape stress-strain curve similar as that of human skin. The Young's modulus, tensile strength and failure strain of the e-skin can be readily adjusted by controlling the content and shape of the CF electrode to match them well with those of human skin. Finally, the fabricated e-skin exhibits the capability of spatiotemporal recognition of the location and magnitude of contact forces in monitoring dynamic stress distribution. The as-prepared stretchable e-skin based on CF/CB/silicone composite is highly promising for robotics and prosthetics, etc.

A radical borylative cyclization reaction of 1,6-dienes was developed to assemble boron-handled six-membered heterocycles and carbocycles. This reaction was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to one of the alkene tethers, followed by an intramolecular 6- exo cyclization to afford a six-membered ring framework. The utility of this method was demonstrated in the synthesis of diverse paroxetine analogues through late-stage derivatization of the boryl functional unit.

In this research, differences in composition, texture characteristics and sensory features of twenty kinds of rice from Heilongjiang China were studied. Experimental results showed significant differences in content of fat, amylose and protein however those differences were not extended to perceived taste evaluation by sensory evaluation. Hardness was measured from 363.6 gs to 1120.3 gs by TPA from 6103.7 g to 11641.1 g adhesiveness, springiness was from 0.4 to 0.6, gumminess was from 2538.9 to 6373.9 and resilience was from 0.2 to 0.3. According to correlate analysis between the chemical composition and taste of rice, we derived that more fat led to more springiness, more protein led to lower viscosity but better hardness and springiness, higher amylose content resulted lower viscosity and taste but higher springiness as well as higher carbohydrate content resulted higher viscosity but lower hardness and springiness. After correlate analysis between chemical composition and the texture characteristic of rice, it was concluded that moisture content was negatively correlated with hardness, gumminess and adhesion, while significantly correlated with resilience; the content of protein was negatively correlated with adhesion but positively correlated with hardness, cohesiveness, gumminess and significantly positively correlated with resilience; the content of ash and adhesion were negatively correlated. The adhesiveness of texture characteristic and the viscosity of taste showed significant positive correlation, and the cohesiveness and resilience of texture characteristic were positively correlated with the softness of taste index.

The human plasma protein binding of water soluble flavonoids in the peels of five spices of citrus fruits was studied by ultrafiltration combined with HPLC. The flavonoids were extracted separately by hot and cold water, and higher total flavonoid contents were detected in the former extracts than the latter ones. All the extracts show significant scavenging abilities to both ABTS and DPPH free radicals, which indicates the health benefits of the water extracts of citrus fruits peels. For DPPH radical, the IC50 values of hot extract follow as Navel orange (NO)≈Mandarin orange (MO)< Lemon (LE)< Lo tangerine (LO)< Pomelo (PO), while the rank is NO< PO

A method for the synthesis of amide-containing molecules was developed using vinyl azides as an enamine-type nucleophile towards carbon electrophiles, such as imines, aldehydes, and carbocations that were generated from alcohols in the presence of BF3 ⋅OEt2 . After nucleophilic attack of the vinyl azide, a substituent of the resulting iminodiazonium ion intermediate migrates to form a nitrilium ion, which is hydrolyzed to afford the corresponding amide.

The oxygen-induced modification of polyacrylonitrile (PAN) fibers during the final stage of thermal-oxidative stabilization is used to control the degree of chemical reactions and the radial structural homogeneity of fibers. A radial structure model for oxidized PAN fibers (OFs) and carbon fibers (CFs) has been established by Raman spectroscopy and wide angle X-ray diffraction. According to the model, the cross-section of OFs is divided into the internal and external regions; the oxygen-induced modification has a greater effect on the structural evolution of internal regions than that of external regions. When the oxygen volume content for the modification is 22.2%, the OFs possess the highest level value for degree of disorder ( DD ) in internal regions. This is inherited by the corresponding CFs with the best radial structure homogeneity and optimum mechanical properties; meanwhile, the coefficient of variation for DD is defined to characterize the radial homogeneity of CFs. The mechanism of the oxygen-induced modification demonstrates that the mechanical properties of the resulting CFs depend on the degrees of the intermolecular cyclization and oxidation which are beneficial to the decrease in CF crystallite size.

The aim of this study was to investigate the expression of nesprin‑1 protein and its effects on rat bone marrow mesenchymal stem cells (MSCs). MSCs were cultured in DMEM and surface-associated antigens of MSCs were detected by flow cytometry. The protein expression of nesprin-1 was detected by immunofluorescence and western blot analysis. A lentiviral vector expressing small interfering RNA (siRNA) targeting nesprin-1 was constructed (LV-siNesprin-1) and the MSCs were subsequently transfected with this vector. Another group of MSCs was transfected with the LV-GFP vector and another group of untransfected cells was used as the controls (normal group). The protein expression level of nesprin-1 in the 3 groups of MSCs (LV-siNesprin-1, LV-GFP and normal group) was measured by western blot analysis. Cell proliferation was assessed by MTT assay, and the cell cycle and apoptosis were detected by flow cytometry. DAPI was used to stain the nucleus of the MSCs. The MSCs appeared spindle-shaped with irregular processes and were positive for CD90, CD29 and negative for CD45. Nesprin-1 protein was found in the nuclear membrane. The protein expression of nesprin-1 in the LV-siNesprin-1 group was lower than that in the LV-GFP (P=0.03) and normal group (P=0.028); this difference was significant (P

d-Phenylglycine-l-Dopa (d-PhG-l-Dopa), designed as a dipeptide mimetic prodrug of dopamine, has been proven to have 31-fold higher oral bioavailability than l-Dopa in rats. To further investigate if this dipeptide enters the brain, a single-dose pharmacokinetic study by i.v. administration, in comparison with l-Dopa, was conducted to monitor brain availability. The dopamine level in the brain was also determined. The results indicated that both d-PhG-l-Dopa and l-Dopa entered the brain rapidly (T max 1 minute) with similar degrees of penetration (AUC brain /AUC plasma 8.83% vs. 7.61%). As d-PhG-l-Dopa had higher systemic exposure than l-Dopa (AUC plasma 23.79 μmol*min/mL vs. 12.09 μmol*min/mL), it thus had higher brain availability (AUC brain 2.0 μmol*min/mL vs. 0.92 μmol*min/mL). Although the AUC brain dopamine after d-PhG-l-Dopa treatment was only 24% of that from l-Dopa treatment, it however exhibited higher anti-Parkinsonism activity than l-Dopa (reduction in rotation number 47.9 ± 5.5% vs. 27.3 ± 4.8%). Higher brain dopamine residual properties of d-PhG-l-Dopa treatment compared to l-Dopa treatment, namely 3.2 times longer MRT brain dopamine (172.15 vs. 53.78 minutes), 10 times longer T max brain dopamine (30 vs. 3 minutes) and 8.36 times longer half-life ( T 1 / 2 T maxtoend ( min ) 112.51 vs. 13.46 minutes), may explain the result. Moreover, the long terminal half-life of brain dopamine upon d-PhG-l-Dopa treatment indicated its slow dopamine-releasing property compared with l-Dopa treatment (112.51 vs. 44.85 minutes). It is also important to note that brain dopamine level was better controlled in the d-PhG-l-Dopa group than in the l-Dopa group (C max /C min 1.62 vs. 9.85). In conclusion, this study demonstrated that d-PhG-l-Dopa is an intrinsic dopamine-sustained-releasing prodrug. The limited concentration fluctuation of released dopamine in the brain is beneficial for the clinical management of Parkinson's disease.

Oxidative skeletal rearrangement of 5-aryl-4,5-dihydro-1,2,4-oxadiazoles into quinazolinones is induced by molecular oxygen (under a dry air atmosphere) that likely proceeds via transient iminyl radical species. Concise syntheses of biologically active quinazolinone derivatives were demonstrated using the present strategy.

The radial structure of polyacrylonitrile (PAN) copolymer fibers was investigated quantitatively by etching layer by layer in an improved permanganic etchant; meanwhile the effect of the etchant on the fiber surface was taken into consideration. The aggregated structure (crystal size, crystallinity, orientation and density) and thermal stability of each circumferential layer of PAN fibers were determined in detail according to a model proposed in the study. A denser layer with a thickness of about 1 µm was observed in the subsurface (2 µm from the PAN fiber surface), possessing a greater crystal size and crystallinity as well as a relatively higher thermal stability than other layers. This layer was considered to be a barrier for the diffusion of oxygen into PAN fibers during the stabilization and accelerated the formation of a core-shell structure in the resulting carbon fibers.

The effects of aerobic and anaerobic conditions on polyhydroxybutyrate (PHB) and glycerin yields during the course of lignin degradation were studied with Pseudomonas stutzeri P156. The lignin degradation rate was 22.5% and 15%, respectively, under aerobic and anaerobic condition. However, the gradation rate/biomass (YL/X) was nearly no differences that diversified from 0.9% to 3%. In addition, the maximal anaerobic yield of PHB and glycerin yield was 0.42 g/g and 56.3 ug/ml, which was 176.6% and 36.7% higher than that under aerobic condition, respectively. Interestingly to point out, anaerobic lignin degradation rate was decreased by 33.3% relative to the aerobic one, but lignin content did decreased by 15% at the cost of higher yields of PHB and glycerin, which suggested biosyntheses of PHB and glycerin could balance the redox potential under anaerobic condition, facilitate lignin degradation by Pseudomonas stutzeri P156, persistently, and meet the process demands of straw-based anaerobic methane fermentation.

To investigate the relationship between nuclear factor Y (NF-Y) and stress tolerance in garlic, we cloned a NF-Y family gene AsNF-YC8 from garlic, which was largely upregulated at dehydrate stage. Expression pattern analyses in garlic revealed that AsNF-YC8 is induced through abscisic acid (ABA) and abiotic stresses, such as NaCl and PEG. Compared with wild-type plants, the overexpressing-AsNF-YC8 transgenic tobacco plants showed higher seed germination rates, longer root length and better plant growth under salt and drought stresses. Under drought stress, the transgenic plants maintained higher relative water content (RWC), net photosynthesis, lower levels of malondialdehyde (MDA), and less ion leakage (IL) than wild-type control plants. These results indicate the high tolerance of the transgenic plants to drought stress compared to the WT. The transgenic tobacco lines accumulated less reactive oxygen species (ROS) and exhibited higher antioxidative enzyme activities compared with wild-type (WT) plants under drought stress, which suggested that the overexpression of AsNF-YC8 improves the antioxidant defense system by regulating the activities of these antioxidant enzymes, which in turn protect transgenic lines against drought stress. These results suggest that AsNF-YC8 plays an important role in tolerance to drought and salt stresses.

In this paper, advanced Fenton-hydroxide precipitation process was proposed to remove synthetic wastewater containing CrEDTA. This process can not only remove chromium, but also reduce COD values. Parameters affecting chromium removal are discussed. At optimum conditions, the chromium removal efficiency attained 87%. Advanced Fenton-hydroxide precipitation process appears a promising and effective method for the treatment of strong stability complex heavy metal containing wastewaters.

Orientation of copolymer polyacrylonitrile (PAN) chains during their deformation prior to stabilization and the further effect on the stabilization were investigated in detail. Results reveal that the orientation of PAN chains presents a saturation point of 69.51% when the deformation ratio reaches approximately 1.07, meanwhile the cyclization rather than the oxidation has a stronger dependence on the orientation of PAN chains during stabilization. The cyclization is facilitated that the cyclization degree is increasing while the activation energy is decreasing obviously as a consequence of the developing orientation of PAN fibers before the saturation point; however, it is restrained during the further deformation of PAN fibers after the point. The resulting carbon fibers obtained from the PAN fibers prepared at the saturation point possess the highest mechanical properties of 4.07 GPa in tensile strength and 249.0 GPa in tensile modulus.

Copper-catalyzed aerobic methyl/methylene oxygenation of substituted indoles and pyrroles was developed using 1,4- diazabicyclo[2.2.2]octane (DABCO) as an additive in dimethyl sulfoxide (DMSO). Similar aerobic catalytic conditions could also be utilized for direct C–H formylation of C(3) on indoles and C(2) on pyrroles.

In situ thermal stretching to modify the conformation of polyacrylonitrile (PAN) chains in quasicrystals and amorphous regions is carried out on PAN copolymer fibers prior to oxidative stabilization. Meanwhile, a model to evaluate the deformation of PAN quasicrystals and amorphous regions is proposed, in which deformation behavior (orientation or extension) and type (elastic or plastic) in the two regions are analyzed. PAN chains exhibit various deformations as a consequence of combined thermal treatment and mechanical stretching. The orientation of PAN chains occurs prior to their extension when the stretching ratio is under 1.06, however, no significant orientation but extension is observed when the deformation ratio ranges from 1.08 to 1.16. As the stretching ratio increases, elastic-dominated orientation of PAN chains is stronger in quasicrystals before 1.03 and is prominent in amorphous regions between 1.04 and 1.08. The mechanical properties of the resulting carbon fibers strongly depend on the orientation degree of PAN chains in amorphous regions.

The total synthesis of ganglioside 2, an analogue of the ganglioside Hp-s1 (1) which displays neuritogenic activity toward the rat pheochromocytoma cell line PC-12 cell in the presence of nerve growth factor (NGF) with an effect (34.0%) greater than that of the mammalian ganglioside GM 1 (25.4%), was accomplished by applying a chemoselective-activation glycosylation strategy. Moreover, we also demonstrate that the synthesized ganglioside 2 exhibited neuritogenic activity toward the human neuroblastoma cell line SH-SY5Y without the presence of NGF.

Triflimide (Tf2NH) specifically catalyzed reactions of alcohols and vinyl azides, enabling efficient construction of amides with C–C bond formation through nucleophilic attack of vinyl azides onto the putative carbocation intermediates derived from alcohols are described.