Mapping Microclimate pH Distribution inside Protein-Encapsulated PLGA Microspheres Using Confocal Laser Scanning Microscopy

The pH in the aqueous pores of poly­(lactide-<i>co</i>-glycolide) (PLGA) matrix, also referred to as microclimate pH (μpH), is often uncontrolled, ranging from highly acidic to neutral pH range. The μpH distribution inside protein-encapsulated PLGA microspheres was quantitatively evaluated using confocal laser scanning microscopy. The fluorescent response of Lysosensor yellow/blue dextran used to map μpH in PLGA was influenced by the presence of encapsulated protein. The nonprotonated form of pyridyl group on the fluorescence probe at neutral pH was responsible for the interference, which was dependent on the type and concentration of protein. A method for correction of this interference based on estimating protein concentration inside the microspheres was established and validated. After correction of the influence, the μpH distribution kinetics inside microspheres was evaluated for different PLGA 50/50 microsphere formulations under physiological conditions for 4 weeks. Generally, the μpH acidity increased with the progression of incubation time. The coincorporation of poorly soluble base, magnesium carbonate, in the microspheres prolonged the appearance of detectable acidity for up to 3 weeks. Co-addition of an acetate buffer was able to control the μpH over a slightly acidic range (around pH 4.7) after two week incubation. Microspheres prepared from a lower polymer concentration exhibited a higher μpH, likely owing to reduced diffusional resistance to acidic degradation products. The stability of protein was enhanced by addition of MgCO₃, acetate buffer, or by reduced polymer concentration in the preparation, as evidenced by more soluble protein recovered after incubation. Hence, the μpH imaging technique developed can be employed in the future for optimization of formulation strategies for controlling μpH and stabilizing encapsulated proteins

sj-pdf-1-pic-10.1177_09544062211027199 - Supplemental material for Machine learning approach to improve vapor recovery: Prediction and frequency converter with a new vapor recovery system

Supplemental material, sj-pdf-1-pic-10.1177_09544062211027199 for Machine learning approach to improve vapor recovery: Prediction and frequency converter with a new vapor recovery system by Yajun Liu, Shenchao Zhang and Zhendong Liu in Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science</p

New Recommendations for Total Weight Gain during Pregnancy According to Pre-pregnancy Body Mass Index.

<p>^aBMI: body mass index</p><p>New Recommendations for Total Weight Gain during Pregnancy According to Pre-pregnancy Body Mass Index.</p

sj-pdf-2-pic-10.1177_09544062211027199 - Supplemental material for Machine learning approach to improve vapor recovery: Prediction and frequency converter with a new vapor recovery system

Supplemental material, sj-pdf-2-pic-10.1177_09544062211027199 for Machine learning approach to improve vapor recovery: Prediction and frequency converter with a new vapor recovery system by Yajun Liu, Shenchao Zhang and Zhendong Liu in Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science</p

Gestational weight gain in China during 2011.

<p>Gestational weight gain in China during 2011.</p

Pregnancy, Peripartum and Neonatal Outcomes According to Maternal Weight Gain.

<p>^aGWG: gestational weight gain</p><p>^bSGA and ^cLGA: small for gestational age and large for gestational age, defined as the < 10th percentile and > 90th percentile, respectively, of sex-specific reference curves.</p><p>^dCS: cesarean section.</p><p>Adequate gestational weight gain: underweight, 12.5–18 kg; normal, 11.5–16 kg; overweight, 7–11.5 kg; and obese, 5–9 kg.</p><p>Pregnancy, Peripartum and Neonatal Outcomes According to Maternal Weight Gain.</p

Joint and Independent Associations of Gestational Weight Gain and Pre-Pregnancy Body Mass Index with Outcomes of Pregnancy in Chinese Women: A Retrospective Cohort Study

<div><p>Objective</p><p>To explore the joint and independent effects of gestational weight gain (GWG) and pre-pregnancy body mass index (BMI) on pregnancy outcomes in a population of Chinese Han women and to evaluate pregnant women’s adherence to the 2009 Institute of Medicine (IOM) gestational weight gain guidelines.</p><p>Methods</p><p>This was a multicenter, retrospective cohort study of 48,867 primiparous women from mainland China who had a full-term singleton birth between January 1, 2011 and December 30, 2011. The independent associations of pre-pregnancy BMI, GWG and categories of combined pre-pregnancy BMI and GWG with outcomes of interest were examined using an adjusted multivariate regression model. In addition, women with pre-pregnancy hypertension were excluded from the analysis of the relationship between GWG and delivery of small-for-gestational-age (SGA) infants, and women with gestational diabetes (GDM) were excluded from the analysis of the relationship between GWG and delivery of large-for-gestational-age (LGA) infants.</p><p>Results</p><p>Only 36.8% of the women had a weight gain that was within the recommended range; 25% and 38.2% had weight gains that were below and above the recommended range, respectively. The contribution of GWG to the risk of adverse maternal and fetal outcomes was modest. Women with excessive GWG had an increased likelihood of gestational hypertension (adjusted OR 2.55; 95% CI = 1.92–2.80), postpartum hemorrhage (adjusted OR 1.30; 95% CI = 1.17–1.45), cesarean section (adjusted OR 1.31; 95% CI = 1.18–1.36) and delivery of an LGA infant (adjusted OR 2.1; 95% CI = 1.76–2.26) compared with women with normal weight gain. Conversely, the incidence of GDM (adjusted OR 1.64; 95% CI = 1.20–1.85) and SGA infants (adjusted OR 1.51; 95% CI = 1.32–1.72) was increased in the group of women with inadequate GWG. Moreover, in the obese women, excessive GWG was associated with an apparent increased risk of delivering an LGA infant. In the women who were underweight, poor weight gain was associated with an increased likelihood of delivering an SGA infant. After excluding the mothers with GDM or gestational hypertension, the ORs for delivery of LGA and SGA infants decreased for women with high GWG and increased for women with low GWG.</p><p>Conclusions</p><p>GWG above the recommended range is common in this population and is associated with multiple unfavorable outcomes independent of pre-pregnancy BMI. Obese women may benefit from avoiding weight gain above the range recommended by the 2009 IOM. Underweight women should avoid low GWG to prevent delivering an SGA infant. Pregnant women should therefore be monitored to comply with the IOM recommendations and should have a balanced weight gain that is within a range based on their pre-pregnancy BMI.</p></div

Proportion of pre-pregnancy body size satisfaction status in gestational weight gain groups.

<p>Proportion of pre-pregnancy body size satisfaction status in gestational weight gain groups.</p

Relative Risk Estimates of Maternal and Neonatal Outcomes in Relation to BMI^a.

<p>^aBMI: body mass index</p><p>^bSGA and ^cLGA: small for gestational age and large for gestational age, defined as the < 10th percentile and > 90th percentile, respectively, of sex-specific reference curves</p><p>^dCS: cesarean section.</p><p>Based on multiple logistic regression models adjusted for maternal age at birth, smoking, alcohol consumption, maternal height, social status defined by education, length of gestation, residential area (urban or rural) and gestational weight gain.</p><p>**Significantly different from the estimate of the reference category (p < 0.01)</p><p>*significantly different from the estimate of the reference category (p < 0.05).</p><p>Relative Risk Estimates of Maternal and Neonatal Outcomes in Relation to BMI<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136850#t002fn001" target="_blank">^a</a>.</p

Risk of Adverse Pregnancy Outcomes According to the Institute of Medicine Guidelines for GWG^a by Adjusted Odds Ratios and 95% Confidence Intervals.

<p>^aGWG: gestational weight gain</p><p>^bsmall for gestational age and ^clarge for gestational age, defined as the < 10th percentile and > 90th percentile, respectively, of sex-specific reference curves;</p><p>^dCS: cesarean section.</p><p>Adequate gestational weight gain: underweight, 12.5–18 kg; normal, 11.5–16 kg; overweight, 7–11.5 kg; and obese, 5–9 kg; Adequate gestational weight gain was set as a reference.</p><p>Based on multiple logistic regression models adjusted for maternal age at birth, smoking, alcohol consumption, maternal height, social status defined by education, length of gestation, residential area (urban or rural) and pre-pregnancy body mass index.</p><p>**Significantly different from the estimate for the reference category (p < 0.01)</p><p>*significantly different from the estimate for the reference category (p < 0.05).</p><p>Risk of Adverse Pregnancy Outcomes According to the Institute of Medicine Guidelines for GWG<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0136850#t004fn001" target="_blank">^a</a> by Adjusted Odds Ratios and 95% Confidence Intervals.</p