Comparative Analysis of the Ultrastructure, Bubble Pores, and Composition of Eggshells of Dwarf Layer-White and Guinea Fowl.

The decrease in eggshell quality seriously affects production efficiency. Guinea fowl (GF) eggs possess strong eggshells because of their unique crystal structure, and few systematic studies have compared laying hen and GF eggs. Sixty eggs were collected from both 40-week-old Dwarf Layer-White (DWL-White) laying hens and GF, and the eggshell quality, ultrastructure, bubble pores, and composition were measured. The results showed that the DWL-White eggs had a higher egg weight and a lower eggshell strength, strength per unit weight, thickness, and ratio than the GF eggs (p < 0.01). There were differences in the mammillary layer thickness ratio, the effective layer thickness ratio, the quantity of bubble pores (QBPs), the ratio of the sum of the area of bubble pores to the area of the eggshell in each image (ARBE), and the average area of bubble pores (AABPs) between the DWL-White and GF eggs (p < 0.01). The composition analysis demonstrated that there were differences in the organic matter, inorganic matter, calcium, and phosphorus between the DWL-White and GF eggs (p < 0.01). There were positive associations between the mammillary knob number in the image and the QBPs and ARBE and a negative correlation with the AABPs in the DWL-White eggs (p < 0.01). This study observed distinctions that offer new insights into enhancing eggshell quality.

Mechanism of Acupuncture in Treating Obesity: Advances and Prospects.

Obesity is a common metabolic syndrome that causes a significant burden on individuals and society. Conventional therapies include lifestyle interventions, bariatric surgery, and pharmacological therapies, which are not effective and have a high risk of adverse events. Acupuncture is an effective alternative for obesity, it modulates the hypothalamus, sympathetic activity and parasympathetic activity, obesity-related hormones (leptin, ghrelin, insulin, and CCK), the brain-gut axis, inflammatory status, adipose tissue browning, muscle blood flow, hypoxia, and reactive oxygen species (ROS) to influence metabolism, eating behavior, motivation, cognition, and the reward system. However, hypothalamic regulation by acupuncture should be further demonstrated in human studies using novel techniques, such as functional MRI (fMRI), positron emission tomography (PET), electroencephalogram (EEG), and magnetoencephalography (MEG). Moreover, a longer follow-up phase of clinical trials is required to detect the long-term effects of acupuncture. Also, future studies should investigate the optimal acupuncture therapeutic option for obesity. This review aims to consolidate the recent improvements in the mechanism of acupuncture for obesity as well as discuss the future research prospects and potential of acupuncture for obesity.

Covalent immobilization of lipase on magnetic biochar for one-pot production of biodiesel from high acid value oil.

Magnetic biochar was synthesized via chelation of Fe3+ with carboxymethyl cellulose and pyrolysis for covalently immobilizing Eversa® Transform lipase. The magnetic biochar had 75.8 mg/g lipase loading that was 54.1 % higher than that without magnetism. The immobilized lipase achieved 91.3 mg/g lipase loading with 19.2 U/mg lipase activity after optimization. It showed good thermal and acid stability with 82.5 % and 98.2 % relative activity at 45 °C and pH 4, respectively. Its relative activity was 90.8 % after stored for 30 d at 4 °C. After magnetically separated for 10 cycles, it still kept 70.1 % activity due to the strong covalent bonding. The lipase further catalyzed one-pot esterification and transesterification of high acid value oil (38 mg KOH/g) with 95.7 % biodiesel yield and cycled for 10 times at 85.7 % yield. Kinetic study gave the activation energy of 28.7 kJ/mol. The covalently immobilized lipase could find practical applications.

Two new anthraquinone derivatives from Saprosma crassipes H. S. Lo.

Two new anthraquinone derivatives sapranquinones A and B (1 and 2) together with two known biogenetically related anthraquinone derivatives (3 and 4) were isolated from the stems of Saprosma crassipes H. S. Lo. The structures of these compounds were elucidated using comprehensive spectroscopic methods. Compounds 1-4 were evaluated for their antibacterial activities and compounds 1 and 3 had a broad spectrum antibacterial activity against Staphylococcus albus, Escherichia coli, Bacillus cereus, Micrococcus tetragenus, and Micrococcus luteus with MIC values ranging from 1.25 to 5 µg/mL.

Estimation of genetic parameters of eggshell translucency and production traits in different genotypes of laying hens.

The translucency of eggshells is a ubiquitous appearance problem caused by moisture translocation and the accumulation of egg contents into the eggshell ultrastructure. Previous studies have mainly investigated the causes of eggshell translucency from nutritional and environmental perspectives. However, little is known of the effect of genetics the causes of eggshell translucency on hen production performance. To evaluate the genetic parameters of eggshell translucency and other production performance indicators, we performed an experiment on 3 pure hen lines: 624 Dwarf Layer-White, 1,612 Rhode Island Red, and 813 Rhode Island Red-White. We collected eggs from each hen over 5 d and measured eggshell translucent level (TL) using the grading method. Additionally we measured indicators of each hen during the laying period, including age at laying of the first egg (AFE), body weight at laying of the first egg (BWFE), weight of the first egg (FEW), body weight at 40 wk (BW40), egg weight at 40 wk (EW40), egg production up to 40 wk of age (EN), and calculated the genetic parameters among the indicators. The results showed that the estimated heritability of TL in the 3 genotypes were 0.30, 0.24, and 0.20, respectively, suggesting a low or moderate level of heritability. We found a positive correlation between TL and AFE, with genetic correlation coefficients 0.19 to 0.41, and negative genetic correlation between TL and EN, with correlation coefficient -0.36 to -0.19. Additionally, we observed positive correlation exists between AFE and FEW, BWFE and FEW, and BW40 and EW40; and negative correlation between AFE and EN in the 3 pure lines. These results enriched the research on heritability of eggshell translucency in different hen breeds and demonstrated moderate or low heritability of the indicator. Furthermore, eggshell translucency was negatively affected by AFE and EN. Our results provide a valuable reference for predicting selection response of eggshell translucency and production performance in brood hens, and locating the genes regulating eggshell translucency.

3D ZnII-Based coordination polymer: Synthesis, structure and fluorescent sensing property for nitroaromatic compounds.

A water-stable ZnII-based coordination polymer (CP) with excellent photophysical behavior, namely [Zn2L(atez)(H2O)2] (compound 1; H3L = 4-(2',3'-dicarboxylphenoxy); atez = 5-aminotetrazole), was successfully prepared by the solvothermal reaction of Zn ions with a π-conjugated and semi-rigid multicarboxylate ligand H3L in the presence of N-containing linker atez. Compound 1 displays a hierarchically pillared three-dimensional (3D) (3,4,5)-connected (4·62) (42·64) (43·64·83) net which is based on two-dimensional (2D) multicarboxylate- ZnII layers strutted by the atez ligands. Sensing investigations of compound 1 reveal that this material can selectively and sensitively detect nitroaromatic compounds in water suspension through fluorescence quenching effect. In particular, it is worth noting that it shows highly specific detection of nitrobenzene (NB) and 2,4,6-trinitrophenol (TNP) with remarkable quenching constants (KSV = 7.5 × 104 M-1 for NB and KSV = 1.9 × 105 M-1 for TNP) and low limit of detection (LOD = 0.93 µM for NB and LOD = 0.36 µM for TNP). Investigations reveal that the probable mechanisms for such sensing processes are the concurrent presence of fluorescence resonance energy transfer (FRET) as well as photoinduced electron transfer (PET) between the CP and nitroaromatic molecules. This work not only offers an effective route to improve the application of fluorescent CPs but also provide one novel probable fluorescence probe for nitroaromatic compounds.

Multifunctional Cd-CP for fluorescence sensing of Cr(VI), MnO4-, acetylacetone and ascorbic acid in aqueous solutions.

The development of multifunctional fluorescent chemosensors for the detection of multiple targets remains challenging but of great importance. In this paper, one novel coordination polymer (CP), denoted as [Cd2(edda)(phen)2]∙H2O (compound 1, H4edda = 5,5' (ethane-1,2-diylbis(oxy)) diisophthalic acid, phen = 1,10-phenanthroline) is successfully designed and prepared under hydrothermal conditions. Structural analysis indicates that compound 1 possesses a one-dimensional (1D) double chain structure, then self-assembles into a three-dimensional (3D) supramolecular framework via π…π interactions between phen molecules. Interestingly, compound 1 is found to be tolerant in wide range of acidic to alkaline aqueous solutions (pH = 2-13). Fluorescent spectral investigations reveal that compound 1 exhibits highly selective and sensitive fluorescence responses toward MnO4-, Cr(VI) ions, acetylacetone (acac) and ascorbic acid (AA) by fluorescence quenching in the aqueous phase. The detection limits are in the very low range, reaching µM level for the detection of MnO4-, Cr(VI) ions, nM for AA and ppm for acac detection. The distinguished multi-responsive performance suggests compound 1 to be a potential multifunctional probe. Furthermore, the possible quenching mechanisms have also been systematically investigated in this work.

Highly efficient removal of hexavalent chromium by magnetic Fe-C composite from reed straw and electric furnace dust waste.

Reed straw and electric furnace dust (EFD) waste were used to prepare magnetic Fe-C composite (EFD&C) by co-precipitation and high-temperature activation method to remove Cr(VI) from water. The magnetic EFD&C owned a large specific surface (536.61 m2/g) and a porous structure (micropores and mesopores), and had an efficient removal capacity for Cr(VI). Under conditions of pH (2), the addition amount of EFD&C (1 g/L), the adsorption time (760 min), and the temperature (45 °C), the maximum adsorption capacity reached 111.94 mg/g. The adsorption mechanism mainly attributed to chemical adsorption (redox), Cr(VI) reduced to Cr(III) by Fe(II) and Fe(0) (from Fe3O4 and Fe components in EFD) and surface functional groups of -OH, C = C, C-C and O-C = O (from biochar), and secondary attributed to physical adsorption, Cr(VI) and Cr(III) (from reduced Cr(VI)) adsorbed into the porous structure of EFD&C. This study provided a feasible solution for the preparation of adsorbents for adsorbing heavy metals from iron-containing metallurgical solid waste and biomass waste, which contributed to reducing the environmental pollution and lowering the cost of adsorbent preparation.

Three new long-chain polyenes from the mangrove-derived fungus Penicillium herquei JX4.

One new epimer pair of long-chain polyenes penicilqueis E (1) and F (2), and one new long-chain polyene pinophol G (3), along with one known compound (4), were obtained from EtOAc extract of the mangrove-derived fungus Penicillium herquei JX4. Their structures were elucidated by detailed analysis of comprehensive spectroscopic data. The inhibitory activities of all compounds against the nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro were evaluated.

Enhancing bacterial cellulose production with hypoxia-inducible factors.

Komagataeibacter xylinus is an aerobic strain that produces bacterial cellulose (BC). Oxygen levels play a critical role in regulating BC synthesis in K. xylinus, and an increase in oxygen tension generally means a decrease in BC production. Fumarate nitrate reduction protein (FNR) and aerobic respiration control protein A (ArcA) are hypoxia-inducible factors, which can signal whether oxygen is present in the environment. In this study, FNR and ArcA were used to enhance the efficiency of oxygen signaling in K. xylinus, and globally regulate the transcription of the genome to cope with hypoxic conditions, with the goal of improving growth and BC production. FNR and ArcA were individually overexpressed in K. xylinus, and the engineered strains were cultivated under different oxygen tensions to explore how their overexpression affects cellular metabolism and regulation. Although FNR overexpression did not improve BC production, ArcA overexpression increased BC production by 24.0% and 37.5% as compared to the control under oxygen tensions of 15% and 40%, respectively. Transcriptome analysis showed that FNR and ArcA overexpression changed the way K. xylinus coped with oxygen tension changes, and that both FNR and ArcA overexpression enhanced the BC synthesis pathway. The results of this study provide a new perspective on the effect of oxygen signaling on growth and BC production in K. xylinus and suggest a promising strategy for enhancing BC production through metabolic engineering. KEY POINTS: • K. xylinus BC production increased after overexpression of ArcA • The young's modulus is enhanced by the ArcA overexpression • ArcA and FNR overexpression changed how cells coped with changes in oxygen tension.

Predictive and prognostic impact of the different features of tumor budding in stage II colorectal cancer.

Tumor budding is a significant independent prognostic factor in colorectal cancer. Routine reporting of tumor budding is now advocated for in the colorectal cancer standard approach recommended by the International Tumor Budding Consensus Conference guidelines. However, the current tumor budding assessment system only emphasizes tumor budding quantity and ignores other features. Therefore, this study aimed to further determine the prognostic value of tumor budding based on a more comprehensive feature analysis. To this end, we conducted a retrospective pathology review of the different characteristics of tumor budding (that is quantity, structure, cell atypia, location, stromal reaction, and immunohistochemical phenotype) in 224 specimens of stage II colorectal cancer at our institution between 2009 and 2015. The mean age of the patients was 60.3±9.2 years (range, 39-84 years). Among various features of tumor budding, single-cell budding, anaplasia-like cell atypia, myxoid stroma, high tumor budding quantity, and loss of CDX2 expression were independent predictors of recurrence and mortality in patients with stage II colorectal cancer. Based on these results, we suggest that in addition to tumor-budding quantity, other tumor budding features play important biological roles in the development of colorectal cancer. Our findings provide prognostic information that could help with guiding clinical management and oncology care models for patients with stage II colorectal cancer.

[Effects of CAAP1 on Proliferation, Migration and Invasion of Hepatoma Cell Line SMMC-7721].

OBJECTIVE: To investigate the effect of caspase activity and apoptosis inhibitor 1 (CAAP1) on the proliferation, migration and invasion of hepatoma cell SMMC-7721. METHODS: pcDNA3/ CAAP1, the overexpression vector of CAAP1, and pSilencer 2.1-U6 neo/shR- CAAP1, the knockdown vector, were constructed and examined. The experiment included 4 groups of SMMC-7721 cells, pcDNA3/ CAAP1 group, pcDNA3 control group, shR- CAAP1 group and pSilencer control group. After the SMMC-7721 cells were cultured, the overexpression vector pcDNA3/ CAAP1 (the pcDNA3/ CAAP1 group), knockdown vector shR- CAAP1 (the shR- CAAP1 group) and their controls (pcDNA3 control group and pSilencer control group) were transfected into SMMC-7721 cells respectively, and the follow-up experiments were carried out 48 h later. The mRNA expression of CAAP1 in each group was examined with qRT-PCR. The protein expression level of CAAP1 and cleaved Caspase-3 were checked with Western blot. The proliferation of cells was examined with CCK-8. The colony formation ability and the motility of cells in each group were assessed with colony formation assay and wound-healing assay, respectively. The migration and invasion of cells were examined with Transwell cell chamber and the apoptosis of cells was examined with flow cytometry. The data of 75 patients with low expression of CAAP1 and 295 patients with high expression of CAAP1 were downloaded from TCGA database and the data of 48 months follow-up were analyzed. Kaplan-Meier survival curve was used to compare the correlation between different levels of CAAP1 expression and overall survival (OS) of hepatocellular carcinoma (HCC) patients. RESULTS: Double enzyme digestion analysis showed that the overexpression vector pcDNA3/ CAAP1 and knockdown vector shR- CAAP1 were constructed successfully. qRT-PCR and Western blot results showed that pcDNA3/ CAAP1 increased the mRNA and protein expression level of CAAP1 in SMMC-7721 cells (in comparison with the pcDNA3 control group, P<0.05), while shR- CAAP1 decreased the mRNA and protein expression of CAAP1 (in comparison with the pSilencer control group, P<0.05). Compared with pcDNA3 control group, the proliferation, colony formation ability, motility, migration and invasion of SMMC-7721 cells in the pcDNA3/ CAAP1 group were increased, while the apoptosis of SMMC-7721 cells was inhibited (all P<0.05). Compared with the pSilencer control group, the proliferation, colony formation ability, motility, migration and invasion ability of SMMC-7721 cells in the shR- CAAP1 group decreased, while the apoptosis increased (all P<0.05). TCGA database analysis showed that HCC patients with low CAAP1 expression had better OS than that of HCC patients with high CAAP1 expression. CONCLUSION: CAAP1 can promote the proliferation, migration and invasion of SMMC-7721 cells while it inhibit their apoptosis.

Effect of WSP, a Chinese Herbal Formula, on Th17/Treg Ratio and HBeAg Seroconversion in Telbivudine-Treated HBeAg-Positive Chronic Hepatitis B Patients with High Baseline ALT Levels (20-30 Times the ULN).

Chronic hepatitis B (CHB) is a global health problem. Clinically, many patients have baseline alanine aminotransferase (ALT) levels above 20 times the upper limit of normal (ULN), but there are few reports about these patients. The prospective randomized placebo-controlled clinical study was designed to investigate the effect of WSP, a Chinese herbal formula, on telbivudine- (LDT-) treated HBeAg-positive CHB patients with high baseline ALT levels (20-30 times the ULN) and kidney-yang deficiency syndrome. Eligible patients were randomized to receive LDT 600 mg/day in combination with WSP (treatment group) or placebo granules (control group) 16.28 g/day for 52 weeks. The results showed that HBeAg seroconversion (SC) rate (44.1%) in the treatment group (n=34) was significantly superior to that (20.6%) in the control group (n=34) at 52 weeks (P < 0.05). Meanwhile, WSP could promote HBV DNA negative conversion (85.3% versus 61.8%, P < 0.05) and ALT normalization (94.1% versus 76.5%, P < 0.05) compared with the placebo. There were no drug-related serious adverse events. During the treatment, the peripheral blood Th17/Treg ratio first increased and then decreased in the treatment group and reached the peak at 12 weeks (P < 0.05). At 12, 24, 36, and 52 weeks, Th17/Treg ratio in the treatment group was better than those in the control group (all P < 0.05). In addition, the patients (n=22) with HBeAg SC had higher Th17/Treg ratio than the patients (n=46) without SC at 12 weeks (0.68±0.26 versus 0.43±0.18, P < 0.001). In conclusion, WSP could safely enhance HBeAg SC and promote HBV DNA negative conversion and ALT normalization in LDT-treated HBeAg-positive CHB patients with high baseline ALT levels (20-30 times the ULN) and kidney-yang deficiency syndrome. Th17/Treg ratio was not only related to the mechanisms of WSP but also a good predictor of 52-week HBeAg SC.

Three cobalt-based coordination polymers with tripodal carboxylate and imidazole-containing ligands: syntheses, structures, properties and DFT studies.

Three cobalt-based coordination polymers [Co(Htatb)(1,3-bimyb)] (1), [Co(Htatb)(bimbp)]·DMF (2), and [Co(Htatb)(1,4-bimyb)]·H2O (3) [H3tatb = 4,4',4''-s-triazine-2,4,6-tribenzoic acid, 1,3-bimyb = 1,3-bis(imidazole-1-ylmethyl)benzene, bimbp = 4,4'-bis(imidazolyl)biphenyl, 1,4-bimyb = 1,4-bis (imidazole-1-ylmethyl)benzene] were synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, IR spectroscopy, UV-vis spectroscopy and elemental analysis. Compound 1 shows a double-strand chain structure, due to the intermolecular O-H⋯O hydrogen bonds and aromatic π-π stacking interactions, the adjacent chains are connected to produce a 3D supramolecular structure. Compound 2 shows a 2D structure with a 1D channel. Compound 3 displays a 2D layer structure, furthermore these layers are joined by O-H⋯O hydrogen bonding to generate a four-fold interpenetrating 3D architecture. The fluorescence properties of 1-3 and the magnetic behavior of 1 and 2 have also been investigated. Based on their crystal structures, compounds 1 and 2 were investigated using hybrid DFT methods at the B3LYP/6-31G (d) level. The DFT-BS approach was applied to study the magnetic coupling behavior. The results reveal that the calculated exchange coupling constants J were in good agreement with the experimental data.

Design and fabrication of a liver-on-a-chip platform for convenient, highly efficient, and safe in situ perfusion culture of 3D hepatic spheroids.

Spheroid-based three-dimensional (3D) liver culture models, offering a desirable biomimetic microenvironment, are useful for recapitulating liver functions in vitro. However, a user-friendly, robust and specially optimized method has not been well developed for a convenient, highly efficient, and safe in situ perfusion culture of spheroid-based 3D liver models. Here, we have developed a biomimetic and reversibly assembled liver-on-a-chip (3D-LOC) platform and presented a proof of concept for long-term perfusion culture of 3D human HepG2/C3A spheroids for building a 3D liver spheroid model. On the basis of a fast and reversible seal of concave microwell-based PDMS-membrane-PDMS sandwich multilayer chips, it enables a high-throughput and parallel perfusion culture of 1080 cell spheroids in a high mass transfer and low fluid shear stress biomimetic microenvironment as well as allowing the convenient collection and analysis of the cell spheroids. In terms of reducing spheroid loss and maintaining cell morphology and viability in long-term perfusion culture, the cell spheroids in the 3D-LOC were more safe and efficient. Notably, the polarisation, liver-specific functions, and metabolic activity of the cell spheroids in 3D-LOC were also remarkably improved and exhibited better long-term maintenance over conventional perfusion methods. Additionally, a robust micromilling method that incorporates secondary PDMS coating techniques (SPCs) for fabricating V-shaped concave microwells was also developed. The V-shaped concave microwell arrays exhibited a higher distribution density and aperture ratio, making it easy to form large-scale and uniform-sized cell spheroids with minimum cell loss. In summary, the proposed 3D-LOC could provide a convenient and robust solution for the long-term safe perfusion culture of hepatic spheroids and be beneficial for a variety of potential applications including development of bio-artificial livers, disease modeling, and drug toxicity screening.

Semirigid Tripodal Ligand Based Uranyl Coordination Polymer Isomers Featuring 2D Honeycomb Nets.

We report five novel uranyl coordination polymers, [(CH3)2NH2]UO2(BTPCA) (1), [(CH3)2NH2]UO2(BTPCA) (2), [(CH3)2NH2]2[UO2(BTPCA)][UO2(BTPCA)]·(H2O)5.5 (3), [(CH3)2NH2]2(UO2)2(BTPCA)2·(H2O)3 (4), and [(CH3)2NH2]UO2(BTPCA) (5), by the utilization of semirigid ligand 1,1',1″-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid (H3BTPCA) and uranyl nitrate through solvothermal reactions. Single-crystal X-ray diffraction analysis reveals that the five compounds share a similar structure composition and local coordination mode to the exclusion of disordered water or DMF molecules. Each UO2(COO)3- motif is connected to six neighboring units through three BTPCA3- ligands, generating an infinite uranyl honeycomb (6, 3) net. The structures of all the five compounds consist of 2D honeycomb nets of various degrees of distortions, which are induced by the flexibility of piperidine rings. The dimethylamine cations and solvent molecules fill in the space between layers. Therefore, these five compounds are isomers in a broad sense. Notably, both compounds 3 and 4 possess 2-fold interpenetrated structures. For compound 5, the distance between the neighboring 2D honeycomb nets is 7.253 Å. This is the largest distance between the 2D honeycomb nets in uranyl-based coordination polymers, to the best of our knowledge. In addition, compounds 1, 2, and 4 are also characterized by infrared spectroscopy (IR), thermogravimetric analysis (TG), powder X-ray diffraction (PXRD), and luminescence properties.

Novel Viologen Derivative Based Uranyl Coordination Polymers Featuring Photochromic Behaviors.

A series of novel uranyl coordination polymers have been synthesized by hydrothermal reactions. Both complexes 1 and 2 prosess two ipbp- ligands (H2 ipbpCl=1-(3,5-dicarboxyphenyl)-4,4'-bipyridinium chloride), one uranyl cation, and two coordination water molecules, which can further extend to 2D networks through hydrogen bonding. In complex 1, two sets of equivalent nets are entangled together, resulting in a 2D + 2D → 3D polycatenated framework. In complex 2, the neighbouring equivalent nets interpenetrate each other, forming a twofold interpenetrated network. Complexes 3 and 4 are isomers, and both of them are constructed from (UO2 )2 (OH)2 dinuclear units, which are connected with four ipbp- ligands. The 3D structures of complexes 3 and 4 are similar along the b axis. Similar to other viologen-based coordination polymers, complexes 3 and 4 exhibit photochromic and thermochromic properties, which are rarely observed in actinide coordination polymers. Unlike the monotonous coordination mode in complexes 1-4, the ipbp- ligands feature a µ3 -bridge through two kinds of coordination modes in complex 5. Notably, complex 5 presents a unique example in which terminal pyridine nitrogen atom is involved in the coordination.

Acceptor Side-Chain Effects on the Excited State Dynamics of Two-Dimensional-Like Conjugated Copolymers in Solution.

Excited state dynamics of two-dimensional-like conjugated copolymers PFDCN and PFSDCN based on alternating fluorene and triphenylamine main chains and malononitrile pendant acceptor groups with thiophene as π-bridge, have been investigated by using transient absorption spectroscopy. There is an additional conjugated -C=C- bond in PFDCN, which distinguishes it from PFSDCN. The lowest energy absorption band of each copolymer absorption spectrum is attributed to the π-π* transition with intramolecular charge-transfer, which has a lower fluorescence contribution than those of higher energy absorption bands. The optical excitation of either PFDCN or PFSDCN solution generates polaron pairs that then self-localize and evolve to a bound singlet exciton within a few picoseconds. Due to the additional conjugated -C=C- bond in the acceptor side-chain, PFDCN has a stronger intramolecular charge-transfer characteristic compared with PFSDCN, therefore exhibiting a longer self-localization time (7 ps vs. 3 ps for PFSDCN) and a shorter fluorescence lifetime (1.48 ns vs. 1.60 ns for PFSDCN).

Acid/Salt/pH Gradient Improved Resolution and Sensitivity in Proteomics Study Using 2D SCX-RP LC-MS.

The usage of strong cation exchange (SCX) chromatography in proteomics is limited by its poor resolution and nonspecific hydrophobic interactions with peptides, which lead to peptide overlap across fractions and change of peptide retention, respectively. The application of high concentration of salt (up to 1000 mM) in SCX also restricted its use in online 2D SCX-RP LC. In the present research, we first exploited the chromatographic ability of online 2D SCX-RP LC by combination of acid, salt, and pH gradient, three relatively independent modes of eluting peptides from SCX column. 50% ACN was added to elution buffer for eliminating hydrophobic interactions between SCX matrix and peptides, and the concentration of volatile salt was reduced to 50 mM. Acid/salt/pH gradient showed superior resolution and sensitivity as well as uniform distribution across fractions, consequently leading to significant improvements in peptide and protein identification. 112 191 unique peptides and 7373 proteins were identified by acid/salt/pH fractionation, while 69 870 unique peptides and 4536 proteins were identified by salt elution, that is, 62.5 and 60.6% more proteins and unique peptides, respectively, identified by the former. Fraction overlap was also significantly minimized by acid/salt/pH approach. Furthermore, acid/salt/pH elution showed more identification for acidic peptides and hydrophilic peptides.

Pharmacokinetic and Pharmacodynamic Efficacies of Continuous versus Intermittent Administration of Meropenem in Patients with Severe Sepsis and Septic Shock: A Prospective Randomized Pilot Study.

BACKGROUND: The antibiotic meropenem is commonly administered in patients with severe sepsis and septic shock. We compared the pharmacokinetic, clinical, and bacteriological efficacies of continuous infusion of meropenem versus intermittent administration in such patients. METHODS: Patients admitted to the Intensive Care Unit (ICU) with severe sepsis or septic shock who received meropenem were randomly assigned to either the continuous (n = 25) or intermittent groups (n = 25). The continuous group received a loading dose of 0.5 g of meropenem followed by a continuous infusion of 3 g/day; the intermittent group received an initial dose of 1.5 g followed by 1 g for every 8 h. Clinical success, microbiological eradication, superinfection, ICU mortality, length of ICU stay, and duration of meropenem treatment were assessed. Serial plasma meropenem concentrations for the first and third dosing periods (steady state) were also measured. RESULTS: Clinical success was similar in both the continuous (64%) and intermittent (56%) groups (P = 0.564); the rates of microbiological eradication and superinfection (81.8% vs. 66.7% [ P = 0.255] and 4% vs. 16% [ P = 0.157], respectively) showed improvement in the continuous group. The duration of meropenem treatment was significantly shorter in the continuous group (7.6 vs. 9.4 days; P= 0.035), where a better steady-state concentration was also achieved. Peak and trough concentrations were significantly different between the continuous and intermittent groups both in the first (Cmax: 19.8 mg/L vs. 51.8 mg/L, P= 0.000; Cmin: 11.2 mg/L vs. 0.5 mg/L, P= 0.000) and third dosing periods (Cmax: 12.5 mg/L vs. 46.4 mg/L, P= 0.000; Cmin: 11.4 mg/L vs. 0.6 mg/L, P= 0.000). For medium-susceptibility pathogens, continuous infusion concentrations above the minimal inhibitory concentration were 100%, which was better than that in the intermittent group. CONCLUSIONS: Continuous infusion of meropenem provides significantly shorter treatment duration and a tendency for superior bacteriological efficacy than intermittent administration. Continuous infusion may be more optimal against intermediate-susceptibility pathogens.