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The lifetime of electronic coherences found in photosynthetic antennas is known to be too short to match the energy transfer time, rendering the coherent energy transfer mechanism inactive. Exciton-vibrational coherence time in excitonic dimers which consist of two chromophores coupled by excitation transfer interaction, can however be much longer. Uncovering the mechanism for sustained coherences in a noisy biological environment is challenging, requiring the use of simpler model systems as proxies. Here, via two-dimensional electronic spectroscopy experiments, we present compelling evidence for longer exciton-vibrational coherence time in the allophycocyanin trimer, containing excitonic dimers, compared to isolated pigments. This is attributed to the quantum phase synchronization of the resonant vibrational collective modes of the dimer, where the anti-symmetric modes, coupled to excitonic states with fast dephasing, are dissipated. The decoupled symmetric counterparts are subject to slower energy dissipation. The resonant modes have a predicted nearly 50% reduction in the vibrational amplitudes, and almost zero amplitude in the corresponding dynamical Stokes shift spectrum compared to the isolated pigments. Our findings provide insights into the mechanisms for protecting coherences against the noisy environment. Photosynthesis in biological systems occurs in a noisy environment that reduces the lifetime of coherences in the excitation energy transfer. Here the author demonstrate that long-lasting coherences are protected by quantum phase synchronization, realized in dimers by exciton-vibrational coupling where energy dissipation occurs predominantly in resonant anti-symmetric collective modes. [ABSTRACT FROM AUTHOR]

Background: Due to radical resection, endoprosthetic reconstruction (EPR) is more invasive and increases the risk of dislocation. Therefore, the suitability of EPR for elderly patients with metastatic tumor needs further investigation. Methods: Seventy-one adult patients with isolated proximal femoral bone metastases who underwent EPR were retrospectively analyzed and stratified into two groups: elderly age group (≥60 years, n = 31) and younger age group (<60 years, n = 40). The effect of age on prognosis was analyzed to determine whether EPR is beneficial in elderly patients with proximal femoral metastatic tumor. Cox regression modeling was used to evaluate the effect of different factors on postoperative survival outcomes. Results: Ten (32.26%) and 9 (22.50%) cases of perioperative complications were recorded in the elderly and younger age groups, respectively, with median survival times of 22.00 ± 4.61 months and 23.00 ± 2.85 months, respectively; a log-rank test showed that the difference was not statistically significant (p = 0.657). A Cox regression model was established with patient age as the covariable to evaluate whether it affected postoperative survival. The risk of death due to age was not significant (p = 0.649), but malignancy and femoral metastasis type were significantly associated with postoperative survival (p = 0.001 and p = 0.019). Conclusion: Although older patients have a slightly higher incidence of postoperative complications than younger patients, they do not experience severe adverse consequences. With rigorous selection and careful preparation, EPR is appropriate for the treatment of proximal femoral metastases in older patients, including those with Harrington type I–II acetabular invasion. [ABSTRACT FROM AUTHOR]

Ferroelectrics are considered excellent photocatalytic candidates for solar fuel production because of the unidirectional charge separation and above-gap photovoltage. Nevertheless, the performance of ferroelectric photocatalysts is often moderate. A few studies showed that these types of photocatalysts could achieve overall water splitting. This paper proposes an approach to fabricating interfacial charge-collecting nanostructures on positive and negative domains of ferroelectric, enabling water splitting in ferroelectric photocatalysts. The present study observes efficient accumulations of photogenerated electrons and holes within their thermalization length (~50 nm) around Au nanoparticles located in the positive and negative domains of a BaTiO3 single crystal. Photocatalytic overall water splitting is observed on a ferroelectric BaTiO3 single crystal after assembling oxidation and reduction cocatalysts on the positively and negatively charged Au nanoparticles, respectively. The fabrication of bipolar charge-collecting structures on ferroelectrics to achieve overall water splitting offers a way to utilize the energetic photogenerated charges in solar energy conversion. While ferroelectric materials are promising candidates for solar water splitting, most examples show poor activities. Here, authors prepare charge-collecting nanostructures on the positive and negative domains of BaTiO3 and demonstrate photocatalytic overall water splitting. [ABSTRACT FROM AUTHOR]

Environmental change and human activity can be recorded in sediment cores in aquatic systems such as lakes. Information from such records may be useful for environmental governance in the future. Six sediment cores were collected from Lake Qinghai, China and its sublakes during 2012 and 2013. Measurements of sediment grain-size fractions indicate that sedimentation in the north and southwest of Lake Qinghai is dominated by river input, whereas that in Lake Gahai and Lake Erhai is dominated by dunes. The sedimentation rates in Lake Qinghai were calculated to be 0.101-0.159 cm/y, similar to the rates in other lakes on the Qinghai-Tibetan Plateau. Using these data and sedimentation rates from the literature, we compiled the spatial distribution of sedimentation rates. Higher values were obtained in the three main areas of Lake Qinghai: two in river estuaries and one close to sand dunes. Lower values were measured in the center and south of the lake. Measurements of total organic carbon (TOC), total nitrogen (TN), phosphorus concentrations, and TOC/TN ratios in three cores (QH01, QH02, and Z04) revealed four horizons corresponding to times of increased human activity. These anthropogenic events were (1) the development of large areas of cropland in the Lake Qinghai watershed in 1960, (2) the beginning of nationwide fertilizer use and increases in cropland area in the lake watershed after 1970, (3) the implementation of the national program 'Grain to Green,' and (4) the rapid increase in the tourism industry from 2000. Profiles of Rb, Sr concentrations, the Rb/Sr ratio, and grain-size fraction in core Z04 indicate that the climate has become drier over the past 100 years. Therefore, we suggest that lake sediments such as those in Lake Qinghai are useful media for high-resolution studies of regional environmental change and human activity. [ABSTRACT FROM AUTHOR]

This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned. [ABSTRACT FROM AUTHOR]

The objective of this investigation was to find a simple method for the production of phenolic-rich products and sugar derivatives via separation of liquefied lignocellulosic materials. After liquefaction, the liquefied products were separated by addition of a sufficient amount of water. It was found that those hydrophobic phenolics could be largely separated from aqueous solutions. Preparation of polyurethane foams using biopolyol and isocyanate was studied. Water was used as an environmentally friendly blowing agent. The factors influencing the cell structure of foams such as catalyst, dosage of blowing agent, and mass ratio of biopolyol to PEG were studied. The microstructure of synthesized foams was characterized by SEM. [ABSTRACT FROM AUTHOR]

Near infrared spectroscopy (NIRS) has been proved to be a powerful analytical tool in different fields. However, because of the low sensitivity in near infrared region, it is a significant challenge to detect trace analytes with normal NIRS technique. A novel enrichment technique called fluidized bed enrichment has been developed recently to improve sensitivity of NIRS which allows a large volume solution to pass through within a short time. In this paper, fluidized bed enrichment method was applied in the determination of trace dimethyl fumarate in milk. Macroporous styrene resin HZ-816 was used as adsorbent material, and 1 L solution of dimethyl fumarate was run to pass through the material for concentration. The milk sample was pretreated to remove interference matters such as protein, fat, and then passed through the material for enrichment; after that, diffuse reflection NIR spectra were measured for the analyte concentrated on the material directly without any elution process. The enrichment and spectral measurement procedures were easy to operate. NIR spectra in 900-1,700 nm were collected for dimethyl fumarate solutions in the concentration range of 0.506-5.060 μg/mL and then used for multivariate calibration with partial least squares (PLS) regression. Spectral pretreatment methods such as multiplicative scatter correction, first derivative, second derivative, and their combinations were carried out to select the optimal PLS model. Root mean square error of cross-validation calculated by leave-one-out cross-validation is 0.430 μg/mL with ten PLS factors. Ten samples in an independent test set were predicted by the model with the mean relative error of 5.33 %. From the results shown in this work, it can be concluded that the NIR technique coupled with on-line enrichment method can be expanded for the determination of trace analytes, and its applications in real liquid samples like milk and juice may also be feasible. [ABSTRACT FROM AUTHOR]

A fast and convenient analytical technique has been suggested to detect dihydroxybenzene (DHB) isomers directly and simultaneously. In 0.1 M HAc-NaAc buffer solution (pH 5.6), the reduction peaks of p -DHB and o -DHB were partly separated by differential pulse voltammetry at the glassy carbon electrode. By adding a surfactant (cetyl pyridinium chloride) to enhance the detection sensitivity and using a semi-derivative technique to improve the separation, p-DHB and o-DHB were detected simultaneously. The linear calibration ranges were 1.2 × 10−6 to 1.0 × 10−4 M for p -DHB and 8.2 × 10−7 to 1.0 × 10−4 M for o -DHB, with detection limits of 3.6 × 10−7 and 2.4 × 10−7 M, respectively. The proposed method has been applied to the direct determination of DHB isomers in water sample, and the results were excellent. [ABSTRACT FROM AUTHOR]

Abstract Sterile and semi-fertile F1 plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n=18) and maternal Sinapis alba (genome SS, 2n=24), BC1 plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F1 plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFlSH) showed that sterile F1 plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F1 plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F1 plants belong to unexpected hybrids. 1 -3 trivalents were detected at meiotic metaphase I of semi-fertile F1 pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase I. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC1 plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase 1, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning. [ABSTRACT FROM AUTHOR]

Integration of a transgene into a C-genome chromosome plays an important role in reducing ecological risk of transgenic Brassica napus. To obtain C-genome transgenic B. napus, herbicide-resistant bar gene was firstly transferred into B. oleracea var. alboglabra mediated by Agrobacterium tumefaciens strain LBA4404. Then using the transgenic B. oleracea as paternal plants and 8 non-transgenic varieties of B. rapa as maternal plants, C-genome transgenic B. napus with bar gene was artificially resynthesized by means of ovary culture and chromosome doubling. Among 67 lines of the resynthesized B. napus, 31 were positive, and 36 were negative according to PCR test for bar gene. At least 2 plants from each line were kept for PPT spray confirmation. The result was in consistence with the PCR test. Genomic Southern blotting of three randomly chosen lines also showed that bar gene had been integrated into the genome of resynthesized B. napus lines. [ABSTRACT FROM AUTHOR]

Confirmation of direct photogeneration of intrinsic delocalized free carriers in small-molecule organic semiconductors has been a long-sought but unsolved issue, which is of fundamental significance to its application in photo-electric devices. Although the excitonic description of photoexcitation in these materials has been widely accepted, this concept is challenged by recently reported phenomena. Here we report observation of direct delocalized free carrier generation upon interband photoexcitation in highly crystalline zinc phthalocyanine films prepared by the weak epitaxy growth method using ultrafast spectroscopy. Transient absorption spectra spanning the visible to mid-infrared region revealed the existence of short-lived free electrons and holes with a diffusion length estimated to cross at least 11 molecules along the π−π stacking direction that subsequently localize to form charge transfer excitons. The interband transition was evidenced by ultraviolet-visible absorption, photoluminescence and electroluminescence spectroscopy. Our results suggest that delocalized free carriers photogeneration can also be achieved in organic semiconductors when the molecules are packed properly. [ABSTRACT FROM AUTHOR]

The aim of the study is to compare the agronomic characteristics, crop quality, water use efficiency (WUE), and fertilizer use efficiency (FUE) of tomato (Lycopersicon esculintum Mill.) between drip fertigation (DI) and negative-pressure fertigation (NPI). Four treatments were evaluated in a greenhouse plot experiment for their effects on soil moisture and soil available nitrogen and plant photosynthetic, nitrogen uptake, fruit quality, yield, irrigation water use efficiency (WUEi), and FUE: (1) NPI fertigation with no nitrogen fertilization (NPI-F0.00); (2) NPI fertigation with 75% conventional fertilization (NPI-F0.75); (3) DI fertigation with no nitrogen fertilization (DI-F0.00); and (4) DI fertigation with 100% conventional fertilization (DI-F1.00). Compared with those under NPI fertigation, the sugar-acid ratio (30%), vitamin C content (34%), soluble solids content (20%), and nitrate concentration (34%) of tomato fruits under DI fertigation decreased. In addition, the WUE across treatments significantly decreased in the order of NPI-F0.75 > NPI-F0.00 > DI-F1.00 > DI-F0.00; notably, compared with NPI, water consumption increased twofold-fold, and WUE decreased by 47% under DI. The apparent recovery efficiency of applied nitrogen, partial factor productivity from applied nitrogen, and agronomic efficiency of applied nitrogen under NPI-F0.75 were greater than those under DI-F1.00. Both DI and NPI were able to maintain a relatively high tomato yield, but NPI performed slightly better. The yield percentage increase from the soil fertility contribution under NPI and DI was greater than 90%. Compared with DI fertigation, NPI fertigation reduced the amount of fertilizer needed without reducing yield or fruit quality and improved WUE and FUE, resulting in better overall use of soil nutrients by tomato plants. [ABSTRACT FROM AUTHOR]