Comparative analysis of the vaginal microbiome of healthy and polycystic ovary syndrome women: a large cross-sectional study.

RESEARCH QUESTION: What are the different features of the vaginal microbiome (VMB) between patients with polycystic ovary syndrome (PCOS) and healthy women? DESIGN: A cross-sectional study was conducted at a single academic university-affiliated centre. A total of 1446 participants were recruited (PCOS group, n =713, control group, n = 733). Vaginal swabs were analysed using 16S rRNA gene sequencing. The diversity and composition of the microbiome were compared between the PCOS group and the control group. Microbial interaction networks and functional prediction were investigated. RESULTS: The PCOS group had a higher alpha diversity than the control group (Shannon P = 0.03, Simpson P = 0.02), and higher intra-group variability was observed in PCOS group (P < 2.2E-16). At the genus level, the proportion of Lactobacillus decreased (85.1% versus 89.3%, false discovery rate [FDR] = 0.02), whereas the proportion of Gardnerella vaginalis and Ureaplasma increased in the PCOS group (5.1% versus 3.3%, FDR = 0.006; 1.2% versus 0.6%, FDR = 0.002, respectively). Lactobacillus acidophilus, Prevotella buccalis and G. vaginalis were identified as the main differential species. L. acidophilus was positively correlated with serum levels of anti-Müllerian hormone (AMH), and triglyceride (P = 2.01E-05, P = 0.004, respectively). P. buccalis was negatively correlated with serum levels of AMH and testosterone (P = 0.002, P = 0.003, respectively). G. vaginalis was positively correlated with serum levels of AMH, oestradiol and progesterone (P = 0.004, P = 0.005, P = 0.03, respectively). The VMB interaction network indicated that Lactobacillus crispus, Prevotella timonensis, and P. buccalis could be key drivers in the PCOS group. Overall, 55 predicted genes were found to be differentially abundant between PCOS and the control (FDRs < 0.25). CONCLUSIONS: The PCOS group had a higher diversity of vaginal microbiome and showed an enhanced level of heterogeneity. The proportion of Lactobacillus in the PCOS group decreased, whereas the proportions of Gardnerella and Ureaplasma increased. These results warrant further research that can validate the correlation between PCOS and VMB.

Effects of ovarian endometrioma aspiration on in vitro fertilization-intracytoplasmic sperm injection and embryo transfer outcomes: a systematic review and meta-analysis.

PURPOSE: To evaluate the effect of ovarian endometrioma aspiration on IVF/ICSI outcomes. METHODS: The PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, and Wanfang databases were searched to identify studies related to the treatment of endometrioma up to October 1, 2020, and the data of 1207 patients from 10 studies were analyzed using STATA. RESULTS: The 10 studies in our analysis included 7 comparing aspiration and surgery and 6 comparing aspiration with no intervention. In the aspiration versus surgery groups, live birth rate [OR 0.97 (95% CI 0.51, 1.85), P = 0.925] and clinical pregnancy rate [OR 1.30 (95% CI 0.95, 1.80), P = 0.105] showed no significant difference between the two groups. Abortion rate [OR 4.26 (95% CI 1.38, 13.08), P = 0.011], the number of oocytes retrieved [mean difference 1.95 (95% CI 0.10, 3.81), P = 0.039], and the estradiol peak on hCG day [mean difference 392.16 (95% CI 230.14, 554.18), P < 0.001] were significantly higher in the aspiration group compared to the surgical group. In the aspiration versus the no intervention group, live birth rate [OR 0.84 (95% CI 0.45, 1.59), P = 0.602] and clinical pregnancy rate [OR 1.25 (95% CI 0.88, 1.77), P = 0.206] were not significantly different between the two groups. The abortion rate [OR 0.31 (95% CI 0.11, 0.88), P = 0.028] and the number of gonadotropin ampoules [mean difference - 3.13 ampoules (95% CI - 4.90, - 1.37), P < 0.001] were significantly lower in the aspiration group compared to the no intervention group. CONCLUSION: Compared with surgical treatment or no intervention treatment, aspiration has less effect on ovarian response, ovarian reserve, and pregnancy outcomes.

In utero and postnatal exposure to environmental tobacco smoke, blood pressure, and hypertension in children: the Seven Northeastern Cities study.

To evaluate the association of environmental tobacco smoke (ETS) exposure with hypertension and blood pressure (BP) in children, a sample of 9,354 children, aged 5-17 years, was studied from seven northeastern cities of China in 2012-2013. The results showesd that significant associations were observed for hypertension with ETS exposure in utero [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.18-1.57], with current major ETS exposure from fathers (1.38, 1.21-1.57) or anyone (1.26, 1.12-1.42), and with intensity of ETS exposure greater than 1 cigarette per day (ORs ranged from 1.20 to 1.35). For SBP, significant associations were only observed in children with major ETS exposure from father and with cigarettes smoking >10/day. When stratified by sex, more significant associations were found in girls than in boys. In conclusion, prenatal and postnatal ETS exposure was significantly associated with increased odds of hypertension in children, especially in girls.

Higher Prevalence of Endometrial Polyps in Infertile Patients with Endometriosis.

AIM: To study whether infertile patients with endometriosis have a higher prevalence of endometrial polyps, and to clarify the characteristics of the pathology of combined polyps. METHODS: Infertile patients who had undergone both hysteroscopy and laparoscopy in Reproductive Hospital Affiliated with Shandong University from January 2014 to May 2017 were enrolled. Patients with and without endometriosis, diagnosed by laparoscopy, were staged and included in the study group and control group, respectively, and the prevalence of polyps was compared. The pathological types of endometrial polyps were analyzed. RESULTS: A total of 414 cases were enrolled in the study group and 3,048 cases in the control group; polyps were diagnosed, with endoscopy, in 1,107 patients. Endometrial polyps were detected by hysteroscopy in 47.83% of the endometriosis group and 29.82% of the control group. The prevalence of endometrial polyps was significantly higher in the endometriosis group than in the control group (p < 0.001) but not significantly different between stages of endometriosis (p = 0.580). The pathological diagnosis included 899 endometrial polyps and 208 polypoid hyperplasia; 66.5% of endometrial polyps were combined with simple hyperplasia. CONCLUSIONS: The infertile patients with endometriosis had a higher prevalence of endometrial polyps, and those polyps are often combined with simple hyperplasia.

Highly enantioselective (-)-sparteine-mediated lateral metalation-functionalization of remote silyl protected ortho-ethyl N,N-dialkyl aryl O-carbamates.

We report the enantioselective, lateral deprotonation of ortho-protected or functionalized tertiary N,N-dialkyl aryl O-carbamates 5-7 (Scheme 2 ) and meta-protected carbamates 14, 15, and 20 (Schemes 5 and 7 ) by s-BuLi/(-)-sparteine and subsequent quench with a variety of electrophiles to give products 11-13 and 16, 17, and 21 in yields up to 96% and enantiomeric ratios up to 99:1. The influence of organolithium reagents, ratio of organolithium/(-)-sparteine pair versus N,N-dialkyl aryl O-carbamate starting materials, temperature, solvents, electrophiles, substituents located ortho or meta to the O-carbamate moiety, and O-carbamate N-substituents was investigated. The identical absolute configuration of the stereogenic center of the major enantiomers of the products, as established by single-crystal X-ray analysis for substrates (S)-11c, (S)-19, and (S)-21a, provides evidence for a consistent stereochemical course in the enantioselective deprotonation. Mechanistic investigations, including an estimate of the configurational stability of the benzyllithium species 9 (starting from 12e; Scheme 8 ) and 23 (starting from 17e; Scheme 9 ), both derived by tin-lithium exchange, and 24 (starting from 20; Scheme 9 ) are reported. The experimental results, together with semiempirical molecular orbital calculations (PM3/SMD), are consistent with a process in which enantioinduction occurs in the deprotonation step (Scheme 11 ).

Lysine-Triggered Polymeric Hydrogels with Self-Adhesion, Stretchability, and Supportive Properties.

Hydrogels, recognized for their flexibility and diverse characteristics, are extensively used in medical fields such as wearable sensors and soft robotics. However, many hydrogel sensors derived from biomaterials lack mechanical strength and fatigue resistance, emphasizing the necessity for enhanced formulations. In this work, we utilized acrylamide and polyacrylamide as the primary polymer network, incorporated chemically modified poly(ethylene glycol) (DF-PEG) as a physical crosslinker, and introduced varying amounts of methacrylated lysine (LysMA) to prepare a series of hydrogels. This formulation was labeled as poly(acrylamide)-DF-PEG-LysMA, abbreviated as pADLx, with x denoting the weight/volume percentage of LysMA. We observed that when the hydrogel contained 2.5% w/v LysMA (pADL2.5), compared to hydrogels without LysMA (pADL0), its stress increased by 642 ± 76%, strain increased by 1790 ± 95%, and toughness increased by 2037 ± 320%. Our speculation regarding the enhanced mechanical performance of the pADL2.5 hydrogel revolves around the synergistic effects arising from the co-polymerization of LysMA with acrylamide and the formation of multiple intermolecular hydrogen bonds within the network structures. Moreover, the acid, amine, and amide groups present in the LysMA molecules have proven to be instrumental contributors to the self-adhesion capability of the hydrogel. The validation of the pADL2.5 hydrogel's exceptional mechanical properties through rigorous tensile tests further underscores its suitability for use in strain sensors. The outstanding stretchability, adhesive strength, and fatigue resistance demonstrated by this hydrogel affirm its potential as a key component in the development of robust and reliable strain sensors that fulfill practical requirements.

Electroactive and Stretchable Hydrogels of 3,4-Ethylenedioxythiophene/thiophene Copolymers.

Hydrogels are conductive and stretchable, allowing for their use in flexible electronic devices, such as electronic skins, sensors, human motion monitoring, brain-computer interface, and so on. Herein, we synthesized the copolymers having various molar ratios of 3,4-ethylenedioxythiophene (EDOT) to thiophene (Th), which served as conductive additives. With doping engineering and incorporation with P(EDOT-co-Th) copolymers, hydrogels have presented excellent physical/chemical/electrical properties. It was found that the mechanical strength, adhesion ability, and conductivity of hydrogels were highly dependent on the molar ratio of EDOT to Th of the copolymers. The more the EDOT, the stronger the tensile strength and the greater the conductivity, but the lower the elongation break tends to be. By comprehensively evaluating the physical/chemical/electrical properties and cost of material use, the hydrogel incorporated with a 7:3 molar ratio P(EDOT-co-Th) copolymer was an optimal formulation for soft electronic devices.

Stretchable, Adhesive, and Biocompatible Hydrogel Based on Iron-Dopamine Complexes.

Hydrogels' exceptional mechanical strength and skin-adhesion characteristics offer significant advantages for various applications, particularly in the fields of tissue adhesion and wearable sensors. Herein, we incorporated a combination of metal-coordination and hydrogen-bonding forces in the design of stretchable and adhesive hydrogels. We synthesized four hydrogels, namely PAID-0, PAID-1, PAID-2, and PAID-3, consisting of acrylamide (AAM), N,N'-methylene-bis-acrylamide (MBA), and methacrylic-modified dopamine (DA). The impact of different ratios of iron (III) ions to DA on each hydrogel's performance was investigated. Our results demonstrate that the incorporation of iron-dopamine complexes significantly enhances the mechanical strength of the hydrogel. Interestingly, as the DA content increased, we observed a continuous and substantial improvement in both the stretchability and skin adhesiveness of the hydrogel. Among the hydrogels tested, PAID-3, which exhibited optimal mechanical properties, was selected for adhesion testing on various materials. Impressively, PAID-3 demonstrated excellent adhesion to diverse materials and, combined with the low cytotoxicity of PAID hydrogel, holds great promise as an innovative option for biomedical engineering applications.

Mach-number-invariant mean-velocity profile of compressible turbulent boundary layers.

A series of Mach-number- (M) invariant scalings is derived for compressible turbulent boundary layers (CTBLs), leading to a viscosity weighted transformation for the mean-velocity profile that is superior to van Driest transformation. The theory is validated by direct numerical simulation of spatially developing CTBLs with M up to 6. A boundary layer edge is introduced to compare different M flows and is shown to better present the M-invariant multilayer structure of CTBLs. The new scalings derived from the kinetic energy balance substantiate Morkovin's hypothesis and promise accurate prediction of the mean profiles of CTBLs.

Delayed Post-Hypoxic Leukoencephalopathy Following Nitrite Poisoning: A Case Report and Review of the Literature.

Background: Delayed post-hypoxic leukoencephalopathy (DPHL) is a demyelinating syndrome that occurs days to weeks after the brain has recovered from a coma. It is caused by the period of hypoxia and is characterized by mental disorders, extrapyramidal system symptoms, and motor changes. Common causes include cardiogenic shock, severe anemia, massive blood loss, and poisoning. Poisoning, mostly resulting from intoxication with carbon monoxide and several narcotic drugs, has been reported to be a cause of DPHL. There are only a few reports of DPHL due to nitrite poisoning in literature. We report DPHL in a patient following nitrite poisoning and a review of the literature in this context. Case Presentation: A 64-year-old man presented with dizziness and nausea without vomiting. He later went into a coma after consuming a spare rib soup. After blood gas analysis, we suspected nitrite poisoning combined with metabolic acidosis, hypoxemia, and electrolyte imbalance. He gradually showed neurologic recovery to premorbid baseline after intravenous administration of methylene blue (40 mg) and symptomatic treatment. Two months later, the patient's cerebral magnetic resonance imaging (MRI) showed signs that are compatible with injury, with the patient in late stages of mental decline. Conclusion: Nitrite poisoning can cause DPHL. There is a period of intermittent recovery between the time of poisoning and the development of DPHL, but the specific pathogenesis and treatment are still unclear.

PAYCS Alleviates Scopolamine-Induced Memory Deficits in Mice by Reducing Oxidative and Inflammatory Stress and Modulation of Gut Microbiota-Fecal Metabolites-Brain Neurotransmitter Axis.

The bioactive peptide PAYCS (Pro-Ala-Tyr-Cys-Ser) identified from anchovy hydrolysates has been reported to be positive in memory alleviation. The gut microbiota-brain axis plays a vital role in brain functions, which could be affected by nutritional supplementation. Herein, we found that PAYCS at different concentrations (PAYCS-L and PAYCS-H) showed various improving effects in behavioral tests and alleviation effects on oxidative as well as inflammatory stress in the scopolamine-induced AD mouse model. The 16S rRNA results illustrated that PAYCS-L altered the ratio of Bacteroidetes/Firmicutes and PAYCS treatment elevated the relative abundance of Cacteroidaceae and Prevotellaceae. Notably, administration of PAYCS significantly upregulated memory-related metabolites and neurotransmitters. Overall, PAYCS-L reversed memory deficits of amnesiac mice partially via the modulation of gut microbiota-metabolites-brain neurotransmitter axis. For PAYCS-H, functions might be involved in the reversal of oxidative and inflammatory impairments in the liver and serum, which was also associated with the changed intestinal microbiota and fecal metabolites.

Synergistic alleviation effects of anchovy hydrolysates-catechin on scopolamine-induced mice memory deficits: the exploration of the potential relationship among gut-brain-axis.

Anchovy protein hydrolysates (APH) and catechin (CA) have proved to be effective in memory improvement. However, the enhancing effects of APH-CA conjugates on the memory are little investigated. The underlying mechanism and synergic effects remain unclear. Herein, relationships among memory enhancement, gut microbiota, fecal metabolites, and neurotransmitters of mice regulated by APH-CA were investigated. APH, APH-CA, and CA decreased MDA, IL-1ß, and TNF-α in liver, altered levels of GPx, LDH, IL-1ß, and TNF-α in serum, re-structured gut microbiota, regulated fecal metabolites, and regulated neurotransmitters in the brain. The alleviation effects of APH-CA were partially better than those of APH and CA. The 16s rRNA results illustrated that Bacteroidetes and Firmicutes were altered. Notably, memory-related metabolites and neurotransmitters were significantly up-regulated by the administration of samples. Moreover, possible connections are observed among the gut microbiota, fecal metabolites, and brain neurotransmitters. Together, the regulation of the microbiota-metabolites-brain-neurotransmitters axis may be one of the mechanisms for APH-CA against scopolamine-induced cognitive deficits. In addition, the synergic effects of APH and CA were partially confirmed.

Growth mechanism of interfacial fluid-mixing width induced by successive nonlinear wave interactions.

Interfacial fluid mixing induced by successive waves, such as shock, rarefaction, and compression waves, plays a fundamental role in engineering applications, e.g., inertial confinement fusion, and in natural phenomena, e.g., supernova explosion. These waves bring nonuniform, unsteady external forces into the mixing zone, which leads to a complex mixing process. The growth rate of the mixing width is analyzed by decomposing the turbulent flow field into the averaged field and the fluctuating counterpart. The growth rate is thus divided into three parts: (i) the stretching or compression (S(C)) effect induced by the averaged-velocity difference between two ends of the mixing zone, (ii) the penetration effect induced by the fluctuations which represent the penetration of the two species into each other, and (iii) the diffusive effect, which is induced by the molecular diffusion and is negligible in high-Reynolds-number flows at Schmidt number of order unity. The penetration effect is further divided into the Richtmyer-Meshkov (RM) effect, which is induced by fluctuations that were deposited by earlier wave interactions, and the Rayleigh-Taylor (RT) effect, which is caused by the fluctuations that arise in an overall acceleration of the mixing zone. During the passage of the rarefaction waves, the mixing zone is stretched, while during the passage of the compression waves or shock waves, the mixing zone is compressed. To illustrate these effects, a physical model of RM mixing with reshock is used. By combining the S(C), RM, and RT effects, the entire evolution of mixing width is restructured, which agrees well with numerical simulations for problems with a wide range of density ratios.

Deciphering biomarkers of endometriosis by proteomic analysis of eutopic endometrium in infertile patients.

AIM: Endometriosis is associated with infertility. The aim of this study was to examine the overall proteomic changes of eutopic endometrium in infertile women with endometriosis. METHODS: Tandem mass tags combined with multidimensional liquid chromatography and mass spectrometry analyses were used to screen the proteomic profiles of eutopic endometrium from infertile patients with endometriosis (N = 4), compared with that from patients without endometriosis (N = 4). Quantitative proteomic analysis, functional categories and significant pathway analysis were investigated subsequently. RESULTS: In total, 6.698 proteins were identified, among which 5,812 proteins were quantified. Compared with controls, proteomic analysis showed some differentially expressed proteins: 16 up-regulated proteins and 23 down-regulated proteins. Bioinformatics analysis indicated that differentially expressed proteins were involved in humoral immune response pathways, antimicrobial humoral response and regulation of nitric oxide biosynthetic process. Besides, our results showed that alpha-1-acid glycoprotein 2, complement factor B and zinc transporter Zip14 were important resources for investigating potential mechanism of infertility in infertile women with endometriosis. CONCLUSIONS: This study provided a reference proteome map of eutopic endometrium from infertile women with endometriosis. The long-term benefits of using those markers to stratify clinical treatment warrant further investigation.

Fabrication and characterization of anchovy protein hydrolysates-polyphenol conjugates with stabilizing effects on fish oil emulsion.

Conjugation between peptides and polyphenols could improve their bioactive and functional properties. The improvement effects of anchovy protein hydrolysates (APH) -polyphenol (catechin (CA), gallic acid (GA), tannic acid (TA)) conjugates were investigated. The content of protein and polyphenols and ratio of polyphenols/peptides in conjugates increased as the number of OH group increased with TA > CA > GA. Results showed that APH-CA and APH-GA exhibited the highest ORAC and ABTS+ scavenging capacity, respectively. Mass spectrometry analysis suggested the highest number of bioactive peptides were identified in APH-CA 5:1 (APH/polyphenols). The physical stability of fish oil emulsions during storage was significantly enhanced by TA 5:1 conjugate followed by CA 5:1 conjugate. The oxidative stability was remarkably elevated by APH-GA 10:1. This was due to the antioxidant capacity and the peptides adsorbed at the interfacial. This study demonstrated that APH-polyphenol conjugates could bring the possibility of utilizing peptides-polyphenols in the nutraceutical and functional food ingredient fields.

Evolution of Rayleigh-Taylor instability under interface discontinuous acceleration induced by radiation.

Rayleigh-Taylor instability (RTI) under radiation background is commonly found in both engineering applications and natural phenomena. In the optically thin and incompressible limit, the corresponding problem can be simplified as an interface discontinuous acceleration (IDA) RTI problem, but to date has only been studied in the linear stage. In this paper, the entire IDA-RTI evolution was studied numerically and theoretically, particularly for the stages beyond the linear stage. The results show that the IDA-RTI problem is equivalent to the classical RTI with the effective acceleration g_{eff}^{*} that is introduced in this work. Moreover, our studies further show that IDA-RTI can occur if and only if g_{eff}^{*}>0 (from heavy fluid to light fluid). This criterion means that IDA-RTI can occur when (i) heavy fluid supports (or accelerates) the light fluid or (ii) the two fluids have the same density, in contrast to the classical RTI problem. Moreover, the quasisteady bubble and spike velocities are theoretically predicted with quantitative accuracy, showing good agreement with the results of numerical simulations in a wide range of density ratios and acceleration configurations.

Effects of the Atwood number on the Richtmyer-Meshkov instability in elastic-plastic media.

The Richtmyer-Meshkov instability of small perturbed single-mode interfaces between an elastic-plastic solid and an inviscid liquid is investigated by theoretical analysis and numerical simulation in this work. A modified model including the Atwood number effect is proposed to describe the long-term behaviors of small perturbations at the solid-liquid interface. In contrast to an effective theoretical model at the solid-vacuum interface, this model is appropriate at different Atwood numbers. Owing to the effect of elastic-plastic characteristics and the density ratio, the evolution of the spike amplitude exhibits nonlinear mechanical behavior. As the absolute value of the Atwood number decreases, the maximum spike amplitude also decreases. To validate this model, an Eulerian finite-difference multicomponent code is adopted to study the time evolution of the spike amplitude at different Atwood numbers. The model coefficients are obtained by analyzing the relevant characteristic statistics collected from the numerical results. Under different initial conditions such as Atwood number and shock strength, the applicability of this modified model is verified by comparing the numerical results with the model profile. The consistency in results signifies that the modified model is not only suitable for specific shock intensity and Atwood number, but also adaptable within a certain range.

Preparation and characterization of a novel colorimetric indicator film based on gelatin/polyvinyl alcohol incorporating mulberry anthocyanin extracts for monitoring fish freshness.

This work aimed to develop a novel colorimetric indicator film for monitoring of food freshness based on gelatin/polyvinyl alcohol matrix incorporated with anthocyanin extracts from mulberry. The color of anthocyanin extracts solutions obviously changed from bright red to dark green in the pH range of 2.0-11.0. FTIR spectra and isothermal titration calorimetry showed that the anthocyanin extracts were successfully combined with gelatin/polyvinyl alcohol matrix by hydrogen binding and electrostatic interaction, which enhanced the stability of anthocyanin. The scanning electric microscopy showed that the compatibility between polyvinyl alcohol and gelatin were improved owing to the addition of anthocyanin extracts. With the anthocyanin extracts addition from 0 to 45 mg/100 mL mixed solution, the tensile strength decreased from 30.80 to 21.01 MPa and the elongation at break increased from 589.22% to 905.86%. The color response of film in buffer solution of different pH were in accordance with anthocyanin extracts solutions, and its color changes were clearly visible with naked eye. Finally, the film was evaluated by a test on monitoring fish spoilage, which presented visible color changes due to volatile nitrogenous compounds formed over time. These results showed that this developed film could be used as an effective method for the monitoring of food freshness.

Dynamic evolution of Rayleigh-Taylor bubbles from sinusoidal, W-shaped, and random perturbations.

Implicit large eddy simulations of two-dimensional Rayleigh-Taylor instability at different density ratios (i.e., Atwood number A=0.05, 0.5, and 0.9) are conducted to investigate the late-time dynamics of bubbles. To produce a flow field full of bounded, semibounded, and chaotic bubbles, three problems with distinct perturbations are simulated: (I) periodic sinusoidal perturbation, (II) isolated W-shaped perturbation, and (III) random short-wave perturbations. The evolution of height h, velocity v, and diameter D of the (dominant) bubble with time t are formulated and analyzed. In problem I, during the quasisteady stage, the simulations confirm Goncharov's prediction of the terminal speed v_{∞}=Frsqrt[Agλ/(1+A)], where Fr=1/sqrt[3π]. Moreover, the diameter D at this stage is found to be proportional to the initial perturbation wavelength λ as D≈λ. This differed from Daly's simulation result of D=λ(1+A)/2. In problem II, a W-shaped perturbation is designed to produce a bubble environment similar to that of chaotic bubbles in problem III. We obtain a similar terminal speed relationship as above, but Fr is replaced by Fr_{w}≈0.63. In problem III, the simulations show that h grows quadratically with the bubble acceleration constant α≡h/(Agt^{2})≈0.05, and D expands self-similarly with a steady aspect ratio ß≡D/h≈(1+A)/2, which differs from existing theories. Therefore, following the mechanism of self-similar growth, we derive a relationship of ß=4α(1+A)/Fr_{w}^{2} to relate the evolution of chaotic bubbles in problem III to that of semibounded bubbles in problem II. The validity of this relationship highlights the fact that the dynamics of chaotic bubbles in problem III are similar to the semibounded isolated bubbles in problem II, but not to that of bounded periodic bubbles in problem I.

Influence of hydrolysis behaviour and microfluidisation on the functionality and structural properties of collagen hydrolysates.

The functionality and structural properties of pig skin hydrolysates with different degrees of hydrolysis (DH, 10% and 20%) and microfluidisation (120MPa), prepared by pepsin and Alcalase® have been investigated in this study. Extensive hydrolysis can significantly improve the absolute value of the zeta potential and surface hydrophobicity. The particle distribution of hydrolysates decreased with increasing DH. The numbers of free sulfhydryl (SH) and disulfide bonds (SS) were significantly increased with increasing DH (p<0.05). Hydrolysates with a lower DH showed a better emulsifying property than those with a higher DH. Microfluidisation led to the transformation of structural and interfacial properties of the hydrolysates and increased the value of the zeta potential, S0, and gel strength. Microfluidisation results in limited breakage of chemical bonds, the number of SS and SH bonds unchanged in the treatment. These results reflect the functionality and structural properties of collagen-rich pig skin hydrolysates.