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The contact angle, as a vital measured parameter of wettability of material surface, has long been in dispute whether it is affected by gravity. Herein, we measured the advancing and receding contact angles on extremely low contact angle hysteresis surfaces under different gravities (1-8G) and found that both of them decrease with the increase of the gravity. The underlying mechanism is revealed to be the contact angle hysteresis and the deformation of the liquid-vapor interface away from the solid surface caused by gradient distribution of the hydrostatic pressure. The real contact angle is not affected by gravity and cannot measured by an optical method. The measured apparent contact angles are angles of inclination of the liquid-vapor interface away from the solid surface. Furthermore, a new equation is proposed based on the balance of forces acting on the three-phase contact region, which quantitatively reveals the relation of the apparent contact angle with the interfacial tensions and gravity. This finding can provide new horizons for solving the debate on whether gravity affects the contact angle and may be useful for the accurate measurement of the contact angle and the development of a new contact angle measurement system.

Background: It has not been solved what kind of needle sensation might influence outcomes of acupuncture treatment. Effects of personality factors on the therapeutic effect of acupuncture have not been investigated. This study aimed to find the effects of the traits of personality on the objective outcome when different acupuncture techniques were used in treating patients with Bell's palsy. Methods: We performed a secondary analysis of a prospective multicenter randomized controlled trial of acupuncture for Bell's palsy. Patients were randomly assigned to the de qi and control groups, respectively. The primary outcome was facial nerve function at month 6. The intensity of each needle sensation was rated by a visual analog scale. Psychosocial factors were assessed by the pretreatment mediator questionnaire; 16 Personality Factor Questionnaire (16PF) was used for assessing personality factors and digit cancellation test for assessing attention. Results: After 6 months, patients in the de qi group had better facial function (adjusted odds ratio [OR]: 4.16, 95% confidence interval [CI]: 2.23–7.78). Path analysis showed that intensity of needle sensation of fullness had direct effect on House-Brackmann (HB) score at month 6. In de qi group, the low HB score on day 1 (OR: 0.13, 95% CI: 0.03–0.45) and the low Social Boldness score (OR: 0.63, 95% CI: 0.41–0.97) in 16PF were associated with better facial function. In control group, low HB score on day 1 (OR: 0.25, 95% CI: 0.13–0.50), low Vigilance score (OR: 0.66, 95% CI: 0.50–0.88), and high Tension score (OR: 1.41, 95% CI: 1.12–1.77) in 16PF were related to better facial function. Conclusions: The needle sensation of fullness could predict better facial function and personality traits might influence outcomes of acupuncture treatment. Both of them should be considered seriously in acupuncture treatment and research.

We present a systematic quality comparison of protein crystals obtained with and without cross-linked protein crystal (CLPC) seeds. Four proteins were used to conduct the experiments, and the results showed that crystals obtained in the presence of CLPC seeds exhibited a better morphology. In addition, the X-ray diffraction data showed that the CLPC seeds method is a powerful tool to obtain high-quality protein crystals. Therefore, we recommend the use of CLPC seeds in preparing high-quality diffracting protein crystals.

Estrone and estradiol are both estrogens with estrone being the less potent form and estradiol being the most potent estrogen. The binding of the latter to cellular regulatory elements stimulates the proliferation of breast cancer cells. A high ratio of estradiol/estrone is related to increased cell proliferation, and is of great importance to understanding of breast cancer mechanisms. 17beta-hydroxysteroid dehydrogenase type 1 and type 2 play important roles in the activation of estrone and inactivation of estradiol. Breast cancer cells T47D, MCF-7, BT 20, and JEG 3 as control cells, were chosen to evaluate the contribution of these two enzymes to the ratio. Twenty four hours after addition of different concentrations of estrone and estradiol, the ratio stabilized to around 9/1 in breast cancer cell lines with high expression of type 1 (T47D, BT 20, and JEG 3), whereas it approached 1/5 in cells with low expression of type 1 (MCF-7). The estradiol/estrone concentration ratio was modified to 9/1 in MCF-7 and HEK-293 cells over-expressing type 1. In T47D and BT 20, this ratio was decreased from 9/1 to nearly 1/5 (19/81 and 17/83 respectively) after type 1 knockdown by specific siRNAs. Type 2 is mainly involved in the conversion of estradiol into estrone. This ratio was decreased from 9/1 to 7/3 after over-expression of type 2 in MCF-7 cells already over-expressing type 1. The ratio was further decreased by the addition of the oxidative cofactor, NAD, to the cell culture to facilitate the estradiol to estrone conversion catalyzed by type 2. These results demonstrate that the estradiol/estrone ratio is controlled by both type 1 and type 2 with an additional contribution by NAD, although type 1 is the first determining factor in the cellular environment compared with type 2 and cofactors. Moreover, kinetic studies were carried out in intact cells as a new approach, using HEK-293 cells over-expressing type 1 and T47D breast cancer cells.

Finding new nucleants to promote protein crystallization is an important task, especially for purposes other than structural determination. Here, we investigated cyclodextrins and its derivative particles, as potential nucleants for protein crystallization. β-Cyclodextrin (β-CD) and its derivatives (including p-toluenesulfonyl-β-cyclodextrin (PTCD), polymer-β-cyclodextrin (PCD), mono-(6-(1,6-hexamethylenediamine)-6-deoxy)-β-cyclodextrin (MHCD) and mercapto-β-cyclodextrin (MCD)) were used as nucleants. The experimental results confirmed that β-CD and its derivatives showed significantly positive effects, promoting protein crystallization and improving crystal quality. A larger number of protein molecules (including lysozyme, catalase, subtilisin A VIII, concanavalin A VI, α-chymotrypsinogen, proteinase K, cellulase, papain, glucose isomerase, hemoglobin, and ribonuclease A XII) attached to the particles usually corresponded to a higher crystallization success rate. More detailed analysis showed that cyclodextrins exhibited the best performance when the overall charge of protein in solution was the opposite to zeta potential of the cyclodextrins particle. Our results showed that cyclodextrins can be useful as nucleants due to the ease of modifying them to suit the crystallization of different proteins, and they can be explored for use in the mass purification of proteins for the biopharmaceutical industry. Furthermore, the phenomenon discovered in this study pointed toward a way to find new nucleants based on the overall charge of proteins in a solution: the nucleants should preferably be the opposite between the overall charge of target protein and the zeta potential of the cyclodextrin particle. [ABSTRACT FROM AUTHOR]

Protein crystallization under a magnetic field is an interesting research topic because a magnetic field may provide a special environment to acquire improved quality protein crystals. Because high-quality protein crystals are very useful in high-resolution structure determination using diffraction techniques (X-ray, neutron, and electron diffraction), research using magnetic fields in protein crystallization has attracted substantial interest; some studies have been performed in the past two decades. In this research field, the hardware is especially essential for successful studies because the environment is special and the design and utilization of the research apparatus in such an environment requires special considerations related to the magnetic field. This paper reviews the hardware for protein crystallization (including the magnet systems and the apparatus designed for use in a magnetic field) and progress in this area. Future prospects in this field will also be discussed. [ABSTRACT FROM AUTHOR]

The successful crystallization of proteins is important because their molecular three-dimensional structures can be obtained through X-ray diffraction when in their crystalline form. Investigation of the crystallization process is beneficial for this purpose. We have reported that protein crystallization is sensitive to audible sound, which is commonly present but is often ignored. Here we investigate the effect of audible sound parameters, especially frequency, on a protein crystallization. We show a significant facilitation of protein crystallization using 5000 Hz audible sound, possible mechanism was also tried to be clarified. Suitably controlled audible sound can be beneficial for promoting protein crystallization. Therefore, audible sound can be used as a simple tool to promote protein crystallization. In addition, the processing of other types of materials may also be affected by audible sound. [ABSTRACT FROM AUTHOR]

Protein crystallizes at specific conditions (correct precipitants, appropriate concentrations of protein and precipitants, suitable pH and correct temperature, etc.). If the conditions are not appropriate, crystallization will not occur. In protein crystallization screening, the target protein is mixed one by one with many chemical agents and then incubated at a set temperature. If the concentrations of the chemical agents and the target proteins are not in a range suitable for crystallization, the crystallization will not occur. To expand the concentration screening space, we propose in this paper a new design of protein crystallization plates for cross-diffusion microbatch and microbatch methods. The new plates have 96 units corresponding to the conditions of the commercial screening kits, and each unit contains four wells for holding the crystallization droplets. By dispensing crystallization droplets to the four wells at different volume ratios of protein to precipitant solutions, we can obtain four different initial concentrations for each unit, and thus a wider concentration range can be screened. The comparison between the screening performance of the new plates and the traditional sitting-drop vapor diffusion plate showed that the new design of the plates exhibited significantly improved results in obtaining more crystallization conditions. [ABSTRACT FROM AUTHOR]

This report describes the modification of crystallization plates by simply oxidizing the surface of the protein wells. The oxidized crystallization plates were tested in standard protein crystallization screening and reproducibility studies. The results showed that the protein wells of the treated plates were smoother and more optically transparent than those of the untreated plates, and more importantly, protein crystallization was significantly promoted after the oxidation treatment. Because there is no change to the routine screening protocol, this method is simple and easy to apply in protein crystallization. [ABSTRACT FROM AUTHOR]

Most protein crystallisation begins from heterogeneous nucleation; in practice, crystallisation typically occurs in the presence of a solid surface in the solution. The solid surface provides a nucleation site such that the energy barrier for nucleation is lower on the surface than in the bulk solution. Different types of solid surfaces exhibit different surface energies, and the nucleation barriers depend on the characteristics of the solid surfaces. Therefore, treatment of the solid surface may alter the surface properties to increase the chance to obtain protein crystals. In this paper, we propose a method to modify the glass cover slip using a self-assembled monolayer (SAM) of functional groups (methyl, sulfydryl and amino), and we investigated the effect of each SAM on protein crystallisation. The results indicated that both crystallisation success rate in a reproducibility study, and crystallisation hits in a crystallisation screening study, were increased using the SAMs, among which, the methyl-modified SAM demonstrated the most significant improvement. These results illustrated that directly modifying the crystallisation plates or glass cover slips to create surfaces that favour heterogeneous nucleation can be potentially useful in practical protein crystallisation, and the utilisation of a SAM containing a functional group can be considered a promising technique for the treatment of the surfaces that will directly contact the crystallisation solution. [ABSTRACT FROM AUTHOR]

Background: The traditional Chinese theory of acupuncture emphasizes that the intensity of acupuncture must reach a threshold to generate de qi, which is necessary to achieve the best therapeutic effect. De qi is an internal compound sensation of soreness, tingling, fullness, aching, cool, warmth and heaviness, and a radiating sensation at and around the acupoints. However, the notion that de qi must be achieved for maximum benefit has not been confirmed by modern scientific evidence. Methods: We performed a prospective multicentre randomized controlled trial involving patients with Bell palsy. Patients were randomly assigned to the de qi (n = 167) or control (n = 171) group. Both groups received acupuncture: in the de qi group, the needles were manipulated manually until de qi was reached, whereas in the control group, the needles were inserted without any manipulation. All patients received prednisone as a basic treatment. The primary outcome was facial nerve function at month 6. We also assessed disability and quality of life 6 months after randomization. Results: After 6 months, patients in the de qi group had better facial function (adjusted odds ratio [OR] 4.16, 95% confidence interval [CI] 2.23-7.78), better disability assessment (differences of least squares means 9.80, 95% CI 6.29- 13.30) and better quality of life (differences of least squares means 29.86, 95% CI 22.33-37.38). Logistic regression analysis showed a positive effect of the de qi score on facial-nerve function (adjusted OR 1.07, 95% CI 1.04-1.09). Interpretation: Among patients with Bell palsy, acupuncture with strong stimulation that elicited de qi had a greater therapeutic effect, and stronger intensity of de qi was associated with the better therapeutic effects. Trial registration: Clinicaltrials.gov no. NCT00685789. [ABSTRACT FROM AUTHOR]

The effect of magnetic fields on water is still a highly controversial topic despite the vast amount of research devoted to this topic in past decades. Enhanced water evaporation in a magnetic field, however, is less disputed. The underlying mechanism for this phenomenon has been investigated in previous studies. In this paper, we present an investigation of the evaporation of water in a large gradient magnetic field. The evaporation of pure water at simulated gravity positions (0 gravity level (ab. g), 1 g, 1.56 g and 1.96 g) in a superconducting magnet was compared with that in the absence of the magnetic field. The results showed that the evaporation of water was indeed faster in the magnetic field than in the absence of the magnetic field. Furthermore, the amount of water evaporation differed depending on the position of the sample within the magnetic field. In particular, the evaporation at 0 g was clearly faster than that at other positions. The results are discussed from the point of view of the evaporation surface area of the water/air interface and the convection induced by the magnetization force due to the difference in the magnetic susceptibility of water vapor and the surrounding air. [ABSTRACT FROM AUTHOR]

Melt electrospinning is a complex process, and many of the processing parameters can impact the result of fiber formation. In this paper, we conducted a systematic investigation on the impacts of the melt electrospinning parameters (including temperature, needle gauge, flow rate and collector speed) on the fiber diameter via an orthogonal design experiment. The straight single fibers were fabricated using melt electrospinning in a direct-writing way with a diameter varied from 9.68  ±  0.93 µm to 48.55  ±  3.72 µm. The results showed that the fiber diameter changed differently against different parameters: when the temperature or needle gauge increased, the fiber diameter increased first and then decreased; when the flow rate increased, the fiber diameter decreased first and then increased; when the collector speed increased, the fiber diameter decreased monotonously. We also found that the collector speed was the most influential factor while the needle gauge was least important in determining the diameter of the fiber. Moreover, the feasibility of melt electrospinning in a direct-writing way as a novel 3D printing technology had been demonstrated by fabricating both uniform and controllable structures with high accuracy, based on the optimal parameters from the orthogonal experiments. The promising results indicated that melt electrospinning can be developed as a powerful technique for fabricating miniatured parts with high resolution and controllable structures for versatile potential applications. [ABSTRACT FROM AUTHOR]

The interaction of DNA with quercetin was studied using scanning electrochemical microscopy and electrochemical impedance spectroscopy at glass carbon electrode. Information such as the surface coverage of the film and apparent rate constant of the redox active probe in solution was obtained. It is deduced that quercetin interacting with DNA forms a kind of electrochemical inactive supramolecular complex. It has been pointed out that the electron transfer on the electrode surface was hindered，therefore the normalized current decreased. The estimation of the electrode coverage and hindrance provided further evidences for information of the interaction of quercetin with DNA. The kinetics constant was obtained from electrochemical impedance spectroscopy.