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Abstract Background Perineal massage, as a preventive intervention, has been shown to reduce the risk of perineal injuries and may have a positive impact on pelvic floor function in the early postpartum period. However, there is still debate concerning the best period to apply perineal massage, which is either antenatal or in the second stage of labor, as well as its safety and effectiveness. Meta-analysis was used to evaluate the effect of implementing perineal massage in antenatal versus the second stage of labor on the prevention of perineal injuries during labor and early postpartum pelvic floor function in primiparous women. Methods We searched nine different electronic databases from inception to April 16, 2024. The randomized controlled trials (RCTs) we included assessed the effects of antenatal and second-stage labor perineal massage in primiparous women. All data were analyzed with Revman 5.3, Stata Statistical Software, and Risk of Bias 2 was used to assess the risk of bias. Subgroup analyses were performed based on the different periods of perineal massage. The primary outcomes were the incidence of perineal integrity and perineal injury. Secondary outcomes were perineal pain, duration of the second stage of labor, postpartum hemorrhage, urinary incontinence, fecal incontinence, and flatus incontinence. Results This review comprised a total of 10 studies that covered 1057 primigravid women. The results of the analysis showed that perineal massage during the second stage of labor reduced the perineal pain of primigravid women in the immediate postpartum period compared to the antenatal period, with a statistical value of (MD = -2.29, 95% CI [-2.53, -2.05], P

A new green water treatment agent, a poly(aspartic acid)-modified polymer (PASP/5–AVA), was synthesized using polysuccinimide and 5-aminovaleric acid (5-AVA) in a hybrid system. The structure was characterized, and the scale and corrosion inhibition performance were carried out with standard static scale inhibition and electrochemical methods, respectively. The mechanism was explored using XRD, XPS, SEM, and quantum chemistry calculations. The results indicated that PASP/5–AVA exhibited better scale and corrosion inhibition performance than PASP and maintained efficacy and thermal stability of the scale inhibition effect for a long time. Mechanistic studies indicated that PASP/5–AVA interferes with the normal generation of CaCO3 and CaSO4 scales through lattice distortion and dispersion, respectively; the combined effect of an alkaline environment and terminal electron-withdrawing -COOH groups can induce the stable C- ionic state formation in -CH2- of the extended side chain, thus enhancing its chelating ability for Ca2+ ions. At the same time, the extension of the side chain length also enhances the adsorption ability of the agent on the metal surface, forming a thick film and delaying the corrosion of the metal surface. This study provides the necessary theoretical reference for the design of green scale and corrosion agents.

The anti-scaling agent poly(aspartic acidic) (PASP) polymers had became a hot research topic based on its peptide bond structures with degradation characteristics. However, it was difficult to control the chain length distributions of the synthesized products, which led to difficulty in determining the scaling mechanism for the peptide bond products. In this paper, PASP/8AC graft modified polymers with a narrow dispersity (Ð) and controllable chain lengths was synthesized via a simple two-step method, and 8-aminooctanoic acid (8AC) was introduced into the peptide bond structure of PASP with main chain lengths of 12. The effects of the side-chain lengths and functional groups on the scale inhibition mechanism were determined. The static scale inhibition results showed that the grafted products had significantly improved scale inhibition efficiencies at low concentrations and good temperature and time stabilities. The inhibition rate for CaSO4 scaling was increased by almost 60 % at a concentration of 3 mg/L. At 5 mg/L, the inhibition rate for CaCO3 scaling was increased by 36 %. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) showed that side chain length extensions improved calcium ion chelation by the PASP and increased calcium scale lattice distortion. This study verified the effects of side chains on PASP scale inhibition and its mechanism. This is of great importance in designing new green water treatment agents.

Abstract Given the special performance of nanosilica with its small size, large specific surface area and high surface activity, nanosilica containing reactive amino group (denoted as SiO2–NH2) and polysuccinimide were allowed to take part in polymerization reaction to afford SiO2–NH2 modified polyaspartic acid (denoted as SiO2–NH2/PASP), a potential polymer scale inhibitor with good water solubility for industrial circulating water. The scale inhibition performance of the as-prepared SiO2–NH2/PASP was evaluated by static scale inhibition test; and its scale inhibition mechanism was explored by means of scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Results indicated that SiO2–NH2/PASP exhibits excellent scale inhibition performance against CaSO4 and CaCO3 at very low concentrations (optimum scale inhibition rate of 100% and 68%, respectively), and the presence of 5 mg/L of SiO2–NH2/PASP greatly increases the inhibition efficiency of CaSO4 and CaCO3 scale by 21% and 53%, obviously higher than that of pure PASP.