Visualization of the Dynamics of Photoinduced Crawling Motion of 4-(Methylamino)Azobenzene Crystals via Diffracted X-ray Tracking.

The photoinduced crawling motion of crystals is a continuous motion that azobenzene molecular crystals exhibit under light irradiation. Such motion enables object manipulation at the microscale with a simple setup of fixed LED light sources. Transportation of nano-/micromaterials using photoinduced crawling motion has recently been reported. However, the details of the motion mechanism have not been revealed so far. Herein, we report visualization of the dynamics of fine particles in 4-(methylamino)azobenzene (4-MAAB) crystals under light irradiation via diffracted X-ray tracking (DXT). Continuously repeated melting and recrystallization of 4-MAAB crystals under light irradiation results in the flow of liquid 4-MAAB. Zinc oxide (ZnO) particles were introduced inside the 4-MAAB crystals to detect diffracted X-rays. The ZnO particles rotate with the flow of liquid 4-MAAB. By using white X-rays with a wide energy width, the rotation of each zinc oxide nanoparticle was detected as the movement of a bright spot in the X-ray diffraction pattern. It was clearly shown that the ZnO particles rotated increasingly as the irradiation light intensity increased. Furthermore, we also found anisotropy in the rotational direction of ZnO particles that occurred during the crawling motion of 4-MAAB crystals. It has become clear that the flow perpendicular to the supporting film of 4-MAAB crystals is enhanced inside the crystal during the crawling motion. DXT provides a unique means to elucidate the mechanism of photoinduced crawling motion of crystals.

CT-Based Radiomics Predicts the Malignancy of Pulmonary Nodules: A Systematic Review and Meta-Analysis.

RATIONALE AND OBJECTIVES: More pulmonary nodules (PNs) have been detected with the wide application of computed tomography (CT) in lung cancer screening. Radiomics is a noninvasive approach to predict the malignancy of PNs. We aimed to systematically evaluate the methodological quality of the eligible studies regarding CT-based radiomics models in predicting the malignancy of PNs and evaluate the model performance of the available studies. MATERIALS AND METHODS: PubMed, Embase, and Web of Science were searched to retrieve relevant studies. The methodological quality of the included studies was assessed using the Radiomics Quality Score (RQS) and Prediction model Risk of Bias Assessment Tool. A meta-analysis was conducted to evaluate the performance of CT-based radiomics model. Meta-regression and subgroup analyses were employed to investigate the source of heterogeneity. RESULTS: In total, 49 studies were eligible for qualitative analysis and 27 studies were included in quantitative synthesis. The median RQS of 49 studies was 13 (range -2 to 20). The overall risk of bias was found to be high, and the overall applicability was of low concern in all included studies. The pooled sensitivity, specificity, and diagnostic odds ratio were 0.86 95% confidence interval (CI): 0.79-0.91, 0.84 95% CI: 0.78-0.88, and 31.55 95% CI: 21.31-46.70, respectively. The overall area under the curve was 0.91 95% CI: 0.89-0.94. Meta-regression showed the type of PNs on heterogeneity. CT-based radiomics models performed better in studies including only solid PNs. CONCLUSION: CT-based radiomics models exhibited excellent diagnostic performance in predicting the malignancy of PNs. Prospective, large sample size, and well-devised studies are desired to verify the prediction capabilities of CT-based radiomics model.

Base water potential but not hydrotime predicts seedling emergence of Medicago sativa under water stress conditions.

We determined the hydrotime model parameters of 10 alfalfa seed lots by incubating seeds at various water potentials in the laboratory. Meanwhile, seedling emergence under drought and salinity conditions in a greenhouse pot experiment, and seedling establishment in the field were determined. Correlation analysis was utilized to detect the relationship between hydrotime model parameters and seedling emergence under water stress conditions. The germination percentage did not differ significantly among seed lots when seeds were incubated at -0.1 MPa, while it differed significantly among seed lots at water potentials of -0.3 and -0.6 MPa. Compared to control conditions, drought and salinity decreased seedling emergence to different extents, depending on seed lots. Seedling emergence in the field differed significantly among seed lots and ranged from 30% to 80%. Ψ b(50) showed a significant correlation with seedling emergence under various conditions and with seedling establishment in the field, while no correlation was observed between θ H, σ φb and seedling emergence and establishment. These results suggest that Ψ b(50) can be used to rank the vigor of alfalfa seed lots and thus predict seedling emergence and establishment under water stress conditions.

Catalytic Emulsion Based on Janus Nanosheets for Ultra-Deep Desulfurization.

Catalytic Janus nanosheets were synthesized by using an anion-exchange reaction between heteropolyacids (HPAs) and the modified ionic-liquid (IL) moieties of Janus nanosheets. Their morphology and surface properties were characterized by using SEM, energy-dispersive spectroscopy (EDS), FTIR spectroscopy, and X-ray photoelectron spectroscopy (XPS) studies. Because of their inherent Janus structure, the nanosheets exhibited good amphipathic character with ILs and oil to form a stable ILs-in-oil emulsion. Therefore, these Janus nanosheets can be used as both emulsifiers and catalysts to perform emulsive desulfurization. During this process, sulfur-containing compounds at the interface could be easily oxidized and efficiently removed from a model oil. Application of this Janus emulsion brings an efficient, useful, and green procedure to the desulfurization process. Compared with the desulfurization catalyzed by using HPAs in a conventional two-phase system, the sulfur removal of dibenzothiophene (DBT) achieved in a Janus emulsion system was improved from 68 to 97 % within 1.5 h. Moreover, this emulsion system could be demulsified easily by simple centrifugation to recover both the nanosheets and the ILs. Owing to the good structural stability of the Janus nanosheets, the sulfur removal efficiency of DBT could still reach 99.9 % after the catalytic nanosheets had been recycled at least six times.

An insight into hydration structure of sodium glycinate from ab initio quantum chemical study.

The hydration structure of sodium glycinate (Na(+)GL(-)) is probed by the Monte-Carlo multiple minimum (MCMM) method combined with quantum mechanical (QM) calculations at the MP2/6-311++G(d,p) level. In the gas phase, the energy of [Na(+)GL(-)]ß is more than 30 kJ mol(-1) higher than [Na(+)GL(-)]α. With higher degrees of hydration, our results indicate that the most stable conformers of [Na(+)GL(-)]∙(H2O)8 were derived from [Na(+)GL(-)]ß instead of [Na(+)GL(-)]α. The stable conformers determined by the conductor-like polarizable continuum model (CPCM) also show that [Na(+)GL(-)]ß is more stable than [Na(+)GL(-)]α in the liquid phase. By analyzing the hydration process, water…water hydrogen bonding interaction will be more preferable than ion…water interaction as the number of water molecules increases. According to the electronic density at the bond critical point on the Na-X bonds (X = O1, O2, N) in the low-energy conformers, Na(+)GL(-) will be dissociated as Na(+) and GL(-) in the bulk water, which is not predicted by the CPCM model. The structure features and the charge redistribution of Na(+)GL(-) will provide a physical explanation for the weakening Na-O1 interaction.

A tree-step computational approach to simplify conformational determination of cellobiose and lactose.

Great theoretical attentions have been paid on the conformational preference of individual molecular building blocks of carbohydrates because it is helpful for assignments of the experimental signals and explorations of the biological implications. A tree-step approach is applied here to simplify the conformational determination of phenyl ß-cellobioside and benzyl ß-lactoside, for which 35 and 23 initial structures are built, respectively. After the high-level calculations, low-energy conformers are determined and then compared with previous experimental and theoretical results. The low-energy conformers are reconstructed in our work for both cellobiose and lactose and the results show a quantitative agreement between the experimental signature and the predicted IR vibration assignment. In addition, two low-energy conformers, which are predicted in our work, have not been reported by the previous work using the traditional method. The tree-step computational approach provides an alternative timesaving and accurate method to focus on determining the preferred conformations of disaccharides.

Ab initio investigation of the first hydration shell of protonated glycine.

The first hydration shell of the protonated glycine is built up using Monte Carlo multiple minimum conformational search analysis with the MMFFs force field. The potential energy surfaces of the protonated glycine and its hydration complexes with up to eight water molecules have been scanned and the energy-minimized structures are predicted using the ab initio calculations. First, three favorable structures of protonated glycine were determined, and the micro-hydration processes showed that water can significantly stabilize the unstable conformers, and then their first hydration shells were established. Finally, we found that seven water molecules are required to fully hydrate the first hydration shell for the most stable conformer of protonated glycine. In order to analyse the hydration process, the dominant hydration sites located around the ammonium and carboxyl groups are studied carefully and systemically. The results indicate that, water molecules hydrate the protonated glycine in an alternative dynamic hydration process which is driven by the competition between different hydration sites. The first three water molecules are strongly attached by the ammonium group, while only the fourth water molecule is attached by the carboxyl group in the ultimate first hydration shell of the protonated glycine. In addition, the first hydration shell model has predicted most identical structures and a reasonable accord in hydration energy and vibrational frequencies of the most stable conformer with the conductor-like polarizable continuum model.

Predicting the preferred conformations of luteolin-4'-O-ß-D-glucoside in gas phase: a comparison of two computational approaches.

A tree-step computational approach has been applied to determine the lowest-energy conformers of luteolin-4'-O-ß-D-glucoside (L4'G). Fifty-seven starting structures of the L4'G have been built, and then by performing with density functional theory (DFT) optimizations and second-order Møller-Plesset (MP2) calculations, the preferred conformations of L4'G are predicted. In order to test the accuracy of the computational approach, a hybrid Monte-Carlo multiple minimum (MCMM)/quantum mechanical (QM) approach is applied to determine the favorable conformers of L4'G. The alternative classification is employed to put similar conformations into the same catalogue according to the dihedral angles among the luteolin rings, glycosidic dihedral angles, and the orientations of hydroxyl and hydroxymethyl groups. The low-energy conformations are located after the optimizations at the HF/6-31G(d) and B3LYP/6-311+G(d) levels. Compared with the hybrid MCMM/QM approach, the tree-step computational approach not only remains accurate but also saves a lot of computing resources.

In vitro culture of blastocystis hominis in three liquid media and its usefulness in the diagnosis of blastocystosis.

BACKGROUND: Blastocystis hominis is a common protozoan in the human intestinal tract and can cause the so-called blastocystosis characterized by diarrhea. To date, its identification has depended on the discovery of vacuolar, granular, amoebic, or cystic forms in stool samples using wet mount smears, iodine staining, trichrome staining, or iron hematoxylin staining. The permanent staining methods provide more positive findings. However, mercuric chloride (HgCl(2))-based polyvinyl alcohol (PVA) and Schaudinn fixative are potentially toxic and dangerous to laboratory personnel and, as hazardous chemicals, present problems with disposal. METHODS: To determine whether in vitro culture could be an environmentally safe alternative, the culture growth of B. hominis in three commercially available liquid media (RPMI 1640, 199 Medium, and Dulbecco's modified Eagle's medium (DMEM)) were observed and compared. The sensitivity and specificity of these culture methods to identify B. hominis were compared with those of existing methods used clinically. RESULTS: Conditions for the anaerobic culture of B. hominis in these media were determined as follows: total inoculum sizes no less than 10(5) cells; pH values ranging from 7.0 to 7.5; concentrations of calf or horse serum ranging from 10% to 30% (vol/vol); basic antibiotics added; peaking times at days 3, 6, and 9 (pH 7.5) or days 4 and 8 (or 9) (pH 7.0) at 37°C. No significant differences were noted in multiplication or generation times for the cultivation of B. hominis (p>0.05). In 56 of 398 positive cases, the short-term in vitro culture method achieved the best performance with regard to sensitivity and specificity of the five studied methods. CONCLUSIONS: With the advantages of environmental safety, convenience in preparation and storage, facility in morphologic discrimination, and outstanding performance in terms of sensitivity and specificity, the in vitro culture method could be applied to identify B. hominis for both clinical diagnosis and field study purposes.

Experimental evaluation of cyadox phototoxicity to Balb/c mouse skin.

BACKGROUND: Cyadox is a veterinary drug mainly used as an effective antimicrobial promoter in animal husbandry. It was reported that the other quinoxaline-1,4-dioxide compounds had phototoxicity, but only few data are reported on phototoxicity of cyadox. This study was performed to evaluate the phototoxicity of cyadox on skin. METHODS: Eighty mice were equally divided into eight groups. Five groups with ultraviolet A (UVA) irradiation for 2 h (21 J/cm2) were administered at doses of 0, 10, 50, 200 mg/kg cyadox and 50 mg/kg olaquindox, respectively, and others as controls without irradiation administered at doses of 0, 200 mg/kg cyadox and 50 mg/kg olaquindox, respectively. Drugs were administered by gavage once daily with a suspension in 0.8% carboxymethyl-cellulose for consecutive 4 days. After administration, a recovery period of 7 days was arranged. Histopathological examination of auricular skin was performed on days 5 and 12. Measurement of auricular thickness, gross pathology and erythema score were conducted once daily. RESULTS: Cyadox groups (200, 50 and 10 mg/kg) with irradiation had erythema and oedema of auricular skin with dose-response relationship, which gradually convalesced after dosing and irradiation ceased. Severe erythema, oedema and necrosis of auricles were observed on olaquindox group with irradiation. CONCLUSION: The phototoxicity of cyadox was mild and reversible, which demonstrated a good safety profile of cyadox in terms of phototoxicity.

[Study on the biological characteristic of Blastocystis hominis: morphology, mode of reproduction and the relation to bacteria].

OBJECTIVE: To observe the reproductive modes of Blastocystis hominis and study the relation between this protozoa and bacteria. METHODS: Using the Iodine and Haematoxylin staining, the morphology of B. h from patients and RPMI 1640 medium were observed. The B. h positive mucous diarrheal specimens were cultured and identified any possible known pathogenic intestinal bacteria. B. h and colibacillus were co-cultured to observe the interaction between them. RESULTS: Four modes of reproduction for B. h were confirmed: binary fission, endodyogeny, multiple fission and budding. The fact that there was no other intestinal pathogens in half of the B. h positive specimens suggested B. h may cause disease independently. B. h and colibacillus were restrained each other. CONCLUSION: B. h reproduces in at least four modes. B. h could be a pathogen and its pathogenesis may be related to micro-ecological changes.

[Change of serum leptin and leptin receptors immunoreactivity in the brain following intraoral infusions of chemical solutions in rats].

AIM: To determining whether the level of serum leptin altered and whether the expression of leptin receptor immunoreactivity changed following taste stimuli. METHODS: After intraoral infusions of chemical solutions, which included 3 mol/L sucrose, 5 mmol/L sodium saccharin, 0.1 mol/L NaCl, 0.01 mol/L HCl, 1 mmol/L quinine H2SO4 and 0.1 mol/L monosodium glutamate, serum leptin concentration were measured by using rat leptin RIA kit. Immunohistochemistry ABC method was used for brain sections with high-specify-goat antiserum against leptin receptors. RESULTS: Comparing with the control group (intraoral infusion of distilled water), the level of serum leptin only in sweet group (sucrose an d saccharin) raised (P < 0.05). Many neuronal cell bodies and dendritic processes showed leptin receptors immunoreactivity (LR-IR) in many brain regions, such as amygdala, hypothalamus, parabrachial nucleus and nucleus of the solitary tract, which had intense relationship with taste and feeding. But the number of positive-stained cells showed no difference in aforementioned brain regions between the taste stimuli group and the control group. CONCLUSION: After intraoral stimuli of sweet substances, the serum leptin concentration increased. LR-IR cells exist in amygdala which plays a critical role in the initiation and guidance of feeding. This findings led us study possible effects of leptin on taste responses. Probably, leptin influences food intake through the sense of taste.