Self-assembly and structures of nanoscale double emulsion droplets through coarse-grained molecular dynamics simulations.

Examples of self-assembled multiple emulsion droplets on the nanometre scale are very rare. In this work, we use coarse-grained (CG) molecular dynamics simulations to study the self-assembly of ternary mixtures consisting of water, n-heptane, and nonionic surfactant tetraethylene glycol monododecyl ether (C12E4). The water volume fractions studied are 1%, 3%, and 5%, respectively. Various nanoscale emulsions are obtained in a spontaneous process. When the water/surfactant volume ratio vm/s = 1.0/1.0, the obtained emulsion droplets are identified as oil-in-water-in-oil (O/W/O) double types, consisting of an oil core, an inner surfactant layer, a water layer, and an outer surfactant layer. The water molecules are distributed around the hydrophilic ends of the surfactants, while the hydrophobic ends of the surfactants wrap the oil cores and penetrate into the oil bulk. Hydrogen-bond interactions among water and the hydrophilic ends of the surfactants form cross-links that stabilize the double emulsion droplets. The sizes of all the oil cores inside the droplets are <6 nm in diameter, even with the highest water volume fraction of 5%. Both the concentration of free water molecules on the order of 10-6 mol/cm3 and the favourable energy change during emulsion formation indicate that the emulsion droplets are thermodynamically stable. In contrast, for vm/s = 1.0/5.5, no double emulsion but a simple water-in-oil emulsion was observed, with morphologies evolving from oblate to bicontinuous phases with an increase in the water volume fraction from 1% to 5%. Our coarse-grained molecular dynamics simulations provide valuable insight for the preparation of nanoscale double emulsions and the characterization of their structures.

Epidemiological and clinical analysis of the outbreak of dengue fever in Zhangshu City, Jiangxi Province, in 2019.

This study analyzed the epidemiological and clinical features of dengue fever in Zhangshu, Jiangxi Province, in 2019 and provided evidence for the diagnosis, treatment, prevention, and control of dengue fever. A total of 718 dengue fever patients in Zhangshu in 2019 were involved. ELISA and qRT-PCR were used for pathogenic detection of dengue virus. Multiple adjuvant therapies were applied, and the condition of patients after treatment was examined. Patients were between the ages of 0.75 and 92 years old, and all of them had a fever. A total of 519 cases had fatigue, and 413 cases had generalized myalgia and bone ache; 356 cases had dry mouth, 289 cases had bitter taste, and 167 cases felt dry and bitter taste; 279 cases had rash, and 93 cases had pruritus; 587 cases had decreased leukocyte, among which, 7 cases had leukocyte lower than 1 × 10 [9]/L; 380 cases had a low platelet count, and the platelet count of 29 cases was lower than 50 × 10 [9]/L; 488 cases had increased aspartic transaminase, and 460 cases had increased alanine aminotransferase; 5 cases had a severe disease. It proved that the majority of dengue fever sufferers were adults, with the main clinical features being fever and rash and the chief injured organs being the blood system, liver, heart, and gastrointestinal tract. Besides, over 40% of patients had dry and bitter taste, and 12 cases had alopecia after discharge. It indicates that the incidence of dengue fever in Zhangshu is closely related to the sudden population flow and imported cases.

Characterizing Self-Assembled Monolayers on Gold Nanoparticles.

A key aspect of nanoscience is to control the assembly of complex materials from a "bottom-up" approach. The self-assembly and self-organization of small ligands at the surface of nanoparticles represent a possible starting route for the preparation of (bio)nanomaterials with precise (bio)physical and (bio)chemical properties. However, surface characterization and elucidation of the structure-properties relationship, essential to envisioning such control, remain challenging and are often poorly investigated. This Topical Review aims to discuss different levels of surface characterization, giving an overview of the experimental and computational approaches that are used to provide insights into the self-assembled monolayer with molecular details. The methods and strategies discussed focus on the characterization of self-assembled monolayers at the gold nanoparticle surface, but most of them could also be applied to other types of nanoparticles.

Computational and Experimental Investigation of the Structure of Peptide Monolayers on Gold Nanoparticles.

The self-assembly and self-organization of small molecules on the surface of nanoparticles constitute a potential route toward the preparation of advanced proteinlike nanosystems. However, their structural characterization, critical to the design of bionanomaterials with well-defined biophysical and biochemical properties, remains highly challenging. Here, a computational model for peptide-capped gold nanoparticles (GNPs) is developed using experimentally characterized Cys-Ala-Leu-Asn-Asn (CALNN)- and Cys-Phe-Gly-Ala-Ile-Leu-Ser-Ser (CFGAILSS)-capped GNPs as a benchmark. The structure of CALNN and CFGAILSS monolayers is investigated using both structural biology techniques and molecular dynamics simulations. The calculations reproduce the experimentally observed dependence of the monolayer secondary structure on the peptide capping density and on the nanoparticle size, thus giving us confidence in the model. Furthermore, the computational results reveal a number of new features of peptide-capped monolayers, including the importance of sulfur movement for the formation of secondary structure motifs, the presence of water close to the gold surface even in tightly packed peptide monolayers, and the existence of extended 2D parallel ß-sheet domains in CFGAILSS monolayers. The model developed here provides a predictive tool that may assist in the design of further bionanomaterials.

Deep-Learning-Based Nanomechanical Vibration for Rapid and Label-Free Assay of Epithelial Mesenchymal Transition.

Cancer is a profound danger to our life and health. The classification and related studies of epithelial and mesenchymal phenotypes of cancer cells are key scientific questions in cancer research. Here, we investigated cancer cell colonies from a mechanical perspective and developed an assay for classifying epithelial/mesenchymal cancer cell colonies using the biomechanical fingerprint in the form of "nanovibration" in combination with deep learning. The classification method requires only 1 s of vibration data and has a classification accuracy of nearly 92.5%. The method has also been validated for the screening of anticancer drugs. Compared with traditional methods, the method has the advantages of being nondestructive, label-free, and highly sensitive. Furthermore, we proposed a perspective that subcellular structure influences the amplitude and spectrum of nanovibrations and demonstrated it using experiments and numerical simulation. These findings allow internal changes in the cell colony to be manifested by nanovibrations. This work provides a perspective and an ancillary method for cancer cell phenotype diagnosis and promotes the study of biomechanical mechanisms of cancer progression.

Emergence and Autochthonous Transmission of Dengue Virus Type I in a Low-Epidemic Region in Southeast China.

Background: Dengue fever is a mosquito-borne febrile illness. Southeast Asia experienced severe dengue outbreaks in 2019, and over 1000 cases had been reported in Jiangxi, a previously known low-epidemic region in China. However, the emergence of a dengue virus epidemic in a non-epidemic region remains unclear. Methods: We enrolled 154 dengue fever patients from four hospitals in Jiangxi, from April 2019 to September 2019. Real-time PCR, NS1 antigen rapid test, and IgM, IgG tests were performed, and 14 samples were outsourced to be sequenced metagenomically. Results: Among the 154 cases, 42 were identified as imported and most of them returned from Cambodia. A total of 113 blood samples were obtained and 106 were identified as DENV-1, two as DENV-2, and five were negative through RT-PCR. All DENV-1 strains sequenced in this study were all classified to one cluster and owned a high similarity with a Cambodia strain isolated in 2019. The evolutionary relationships of amino acid were consistent with that of nucleotide genome result. The sequence-based findings of Jiangxi strains were consistent with epidemiological investigation. Conclusion: Epidemiological analysis demonstrated that the emergence of dengue cases led to autochthonous transmission in several cities in Jiangxi, a low-epidemic region before. This study emphasized future prevention and control of dengue fever in both epidemic and non-epidemic regions.

Laser-induced depletion of ultrathin PFPE lubricants using a quantitative coarse-grained model.

Knowledge of laser-pulsed processing of ultrathin liquids on solid surfaces is of great importance in advancing the understanding of synthesis, characterization and applications of functional nanofilms. In this work, we performed molecular dynamics simulations coupled with a novel quantitative coarse-grained model to study laser-induced local heating and depletion behaviors of Fomblin Z2000 lubricants. It was found that the Fomblin lubricant films experience severe evaporation and thermodiffusion-related degradation under laser heating. The ultrathin lubricants inevitably lose their frictional resistance under extremely high temperatures and thermal gradients (i.e., up to 990 K and 65.4 K/nm) that are required for FePt media in HAMR systems. The factors that influence the local thermal depletion, such as laser power, spot size, and scanning velocity, were investigated as well. The results clearly show that the laser power has the greatest influence on the relative maximum temperature change and subsequently the severe lubricant film depletion during rapid laser heating, while the spot size and scanning velocity play a relatively weaker role in the laser-induced local thermal instability. The findings in this work are thus believed to provide molecular scale insights into laser-induced local heating and depletion of ultrathin lubricant films from a precise quantitative perspective.

WITHDRAWN: Epidemiology and clinical analysis of the breakout of dengue fever in Zhangshu City, Jiangxi Province in 2019.

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[Clinical study on different operation procedure for hysterectomy].

OBJECTIVE: To investigate the effects and outcomes of four procedures for hysterectomy. METHOD: Retrospectively, we analyzed the clinical characteristics of 756 cases who respectively received hysterectomy by total abdominohysterectomy (TAH, 260 cases), modified abdominohysterectomy (MAH, 180 cases), transvaginal hysterectomy (TVH, 106 cases), or laparoscopic assisted vaginal hysterectomy (LAVH) (210 cases) and compared their effects and outcomes. RESULTS: The average operation time of TAH (98 +/- 23) minutes, MAH (67 +/- 18) minutes, TVH (63 +/- 19) minutes and LAVH (99 +/- 35) minutes. The average operation time of LAVH and TAH groups was significantly longer than that of TVH and MAH groups (P < 0.05). The volume of hemorrhage during operation in TAH group (180 +/- 49) ml was much more than that of other three groups significantly [MAH (102 +/- 43) ml, TVH (93 +/- 31) ml, LAVH (111 +/- 39) ml]. The average time of antibiotic administration and bowel function recovery in TAH group [(5.2 +/- 2.6) days, (36 +/- 9) hours] was significantly longer than that of TVH [(3.2 +/- 1.6) days, (21 +/- 4) hours], LAVH [(3.5 +/- 1.9) days, (23 +/- 6) hours] and MAH [(3.3 +/- 1.7) days, (23 +/- 7) hours] (P < 0.05). The incidence of fever in TAH group was significantly higher than that of other three groups also. The average hospital stay after operation in TVH [(3.3 +/- 1.2) days] and LAVH [(3.6 +/- 1.1) days] groups was significantly shorter than that of MAH [(5.6 +/- 1.9) days] or TAH [(5.4 +/- 2.3) days] groups (P < 0.05). CONCLUSIONS: Different procedures for total hysterectomy have their own advantages and disadvantages. Microinvasive surgery by laparoscopy for hysterectomy will be mainstream in the future.

[Soil moisture content and fine root biomass of rubber tree (Hevea brasiliensis) plantations at different ages].

By using soil core sampling method, this paper studied the soil moisture regime of rubber plantations and the fine root biomass of Hevea brasiliensis in immature period (5 a), early yielding period (9 a), and peak yielding period (16 a). With the increasing age of rubber trees, the soil moisture content of rubber plantations increased but the fine root biomass decreased. The soil moisture content at the depth of 0-60 cm in test rubber plantations increased with soil depth, and presented a double-peak pattern over the period of one year. The fine root biomass of rubber trees at different ages had the maximum value in the top 10 cm soil layers and decreased with soil depth, its seasonal variation also showed a double-peak pattern, but the peak values appeared at different time. Soil moisture content and soil depth were the main factors affecting the fine root biomass of H. brasiliensis.

[Coupling effects of water and chemical fertilizers on Hevea brasiliensis latex yield].

Water and nutrient are the two main factors limiting Hevea brasiliensis growth and its latex yield. With 17 year-old Clone SCATC 7-33-97 H. brasiliensis as test material, the coupling effects of water and chemical N, P and K fertilizers on latex yield were studied by general orthogonal rotation design of quadratic regression with four factors and five levels under field condition, and a regressive mathematical model was set up based on the latex yield by quadratic regression analysis. The results showed that all test coupling levels of water and chemical fertilizers had significant effects on the latex yield. The yield-increasing effect of test factors was in the order of N application rate > irrigation amount > P application rate > K application rate, while the coupling effect of water and chemical fertilizers was in the sequence of water and N > N and P > water and P > water and K. There was a negative coupling effect of K application rate and soil moisture content. For latex yield, the optimum application rates of chemical fertilizers were 476.39 kg x hm(-2) of urea, 187.70 kg x hm(-2) of superphosphate and 225.77 kg x hm(-2) of potassium chloride, and the optimum irrigation amount was to have 82.78% soil relative water content.

Gestational trophoblastic disease following in vitro fertilization.

BACKGROUND: Gestational trophoblastic disease (GTD) after fertility therapy seems to be a rare complication despite the widespread use of these treatments. Despite embryos derived from normally fertilized oocytes were transferred, molar pregnancies still occurring. CASES: Two patients underwent first cycle of in vitro fertilization (IVF) for management of infertility related to tubal obstruction. GTD was diagnosed by histopathology. CONCLUSION: It is unlikely that this complication is directly related to the technique of IVF itself but rather the characteristics of women and the partner attending for assisted conception make them more at risk of molar pregnancies. The management includes prompt curettage and regular follow-up.