Cd Rates Research Articles

Attenuating Effect of an Extract of Cd-Hyperaccumulator Solanum nigrum on the Growth and Physio-chemical Changes of Datura innoxia Under Cd Stress

PurposeThe use of plant extracts obtained from plants that are highly tolerant to heavy metal toxicity has been beneficial in improving the growth of plants grown under metal toxicity conditions. A lab experiment was performed to elucidate the alleviating role of foliar applied cadmium (Cd)-hyperaccumulator Solanum nigrum (S. nigrum) extract on Datura innoxia (D. innoxia) plants grown under Cd stress (0, 50, and 100 mg Cd kg-1 soil).MethodsGrowth parameters, photosynthetic pigment content, osmo-metabolic compounds, reduced glutathione and phytochelatins content, oxidative damage, and lignin content and its related enzyme (cell wall-bound peroxidase, POX) were determined.ResultsApart from the foliar application response of S. nigrum leaf extract (SNE) in either Cd exposed or non-Cd exposed plants, growth parameters of D. innoxia plant grown under both Cd concentrations (50 and 100 mg Cd kg-1 soil) in terms of root and shoot fresh, dry weight, length, and leaf area were noticeably diminished by 29 and 51%, 29 and 54%, 35 and 70%, 40 and 53%, 30 and 69%, 40 and 60%, and 11 and 23%, respectively, compared with untreated control plants. Foliar delivered SNE secured the photosynthetic pigment, free amino acids, soluble proteins, and soluble sugar content. Additionally, it lessened the adverse effects of Cd stress on D. innoxia plants by curtailing the content of hydrogen peroxide (H2O2) and malondialdehyde (MDA) by 28 and 27%, and 21 and 23%, respectively, compared with the plants subjected to 50 and 100 mg Cd kg-1 only. The findings herein indicated that the plant water extract and their interactions in the investigated Cd rates significantly augmented phenolics, alkaloids, reduced glutathione and phytochelatins content. Cell wall stiffening in D. innoxia indicated that lignin content and POX were significantly higher in plants exposed to 100 mg Cd kg-1 soil displaying increase values of 275 and 300%, respectively, against non-Cd treated control. The magnitude of increment imposed by Cd stress was lessened by using SNE that reflects on adequate cell growth advocated by limited lignification, in terms of lignin content, and downregulated POX activity. Owing to SNE application, root and leaves Cd contents were efficiently reduced reflecting apparent plant liveliness compared with the SNE non-treated Cd-stressed plants.ConclusionsThe outcomes of this study designate that foliar application of the Cd-hyperaccumulator S. nigrum leaf extract can be counted as an unconventional and innovative approach in the alleviation of Cd stress and can be employed as integrated practice when Cd-contaminated regions were exploited for sustainable agriculture of the multipurpose plants.

Mechanisms of CdTe(100) sublimation

The results of accelerated molecular dynamics and energetics calculations of the binding energies, barriers, and prefactors for various stages of desorption from the Cd-terminated and (2 × 1) Te-terminated surfaces of CdTe(100) are presented. Our results indicate that while the desorption barriers for Te2 on the Cd-terminated (100) surface are quite large, the corresponding prefactors are also extremely large. As a result, Cd desorption is the rate-limiting step for the case of sublimation via vacancy pit nucleation and growth, while the corresponding desorption barriers are in good agreement with the effective activation energy obtained in experiments for T>360∘C. A detailed analysis which takes into account our results for the Cd and Te2 desorption rates also leads to good quantitative agreement with the experimentally determined sublimation rate over this temperature range. In contrast, our results indicate that for T<360∘C the desorption of isolated Cd atoms on the (2×1) Te-terminated surface may play an important role. The corresponding desorption barrier (Ed≃1.4 eV) is close to that found experimentally over this temperature range.

Comparison of the ICP OES viewing modes efficiency in the estimation of cadmium (Cd) and lead (Pb) in whole blood samples

In forensic toxicology, precise determination of toxic trace metals in biological samples is critical. Inductively coupled plasma optical emission spectrometry (ICP OES), which has a low limit of detection, high sensitivity, accurate testing, and high analytical efficiency, is one of the most widely used techniques for determining the level of toxic trace metals in biological samples. This study aimed to assess the efficiency of ICP-OES in estimating cadmium (Cd) and lead (Pb) in whole blood samples when viewed axially, dual, and radially. All the samples that were analyzed were digested in 1.5 ml HNO3 and 2 ml H2O2. Selectivity, linearity, recovery, limits of detection (LOD), and quantification (LOQ) were used to validate the system. Cd-axial and radial recovery values were between 82–96 and 84–97%, while Pb-axial and radial recovery values were between 85–94 and 83–99%. Dual Cd-axial and radial recovery values were between 80–92 and 82–94%, while dual Pb-axial and radial recovery values were between 77–92 and 75–96%. The results demonstrated that the axillary and radially view is preferable to the dual view when using separate axially and radially view inductively coupled plasmas (ICP). In axillary and radially views, Cd's recovery rates were better than Pb's in the separate mode, but overall they were satisfactory. The recovery values for Cd and Pb in the dual view were acceptable but not sufficient.

Effect of analcite on cadmium phytoavailability and phytotoxity

The interactive effects of Cd and natural siliceous mineral analcite on Cd phytotoxicity and rate of accumulation in plant tissues have been analyzed. The test-plants of corn and hemp were grown in pots under controlled conditions of light, temperature, and soil moisture for 21 days in experiments modeling the following treatments: (1) without any amendments (control); (2) with the application of 0.1 % and 0.5 % (by weight) of CdSO4; (3) Cd salts (CdSO4) + analcite 0.1 g, 0.25 g, and 0.5 g per container. Test-plants performance was assessed by their growth characteristics (shoot height and root length), the content of photosynthetic pigments, macro- and micronutrients in leaves. The effect of Cd on maize and hemp plants inhibited their growth, chlorophyll biosynthesis in the leaves, led to a change in the balance of macro- and microelements, which leads to the accumulation of Cd in the tissues of shoots of both studied crops. Application of analcite partially compensated for the negative effects of Cd salts on the crop’s growth, chlorophyll content, and balance of nutrients and reduced Cd accumulation significantly in shoots.

Increased fluctuation of sulfur alleviates cadmium toxicity and exacerbates the expansion of Spartina alterniflora in coastal wetlands

Evidence suggests that the invasion of Spartina alterniflora (S. alterniflora) poses potentially serious risks to the stability of coastal wetlands, an ecosystem that is extremely vulnerable to both biological and non-biological threats. However, the effects and mechanisms of sulfur (S) in mediating the growth and expansion of S. alterniflora are poorly understood, particularly when sediments are contaminated with cadmium (Cd). A 6-month greenhouse study was conducted to evaluate the mediating effect of S on Cd tolerance and growth of S. alterniflora. Treatments consisted of a factorial combination of three S rates (applied as Na2SO4; 0, 500, 1000 mg kg−1 dry weight (DW), as S0, S500, and S1000) and four Cd rates (applied as CdCl2; 0, 1, 2, 4 mg kg−1 DW, as Cd0, Cd1, Cd2, and Cd4). Results showed that although the exogenous S supply obviously increased Cd accumulation in roots (up to 71.22 ± 6.43 mg kg−1 DW) due to the decrease of Fe concentration in iron plaque (down to 4.02 ± 1.18 mg g−1 DW), biomass reduction and oxidative stress in plant tissues were significantly alleviated. The addition of S significantly up-regulated the concentration of compounds related to Cd tolerance, including proline and glutathione. Therefore, the translocation of Cd was restricted, and plant growth was not impacted. The present study demonstrated that the exogenous sulfur supply could promote the growth of S. alterniflora and enhance its tolerance to Cd. Therefore, under the effects of S. alterniflora, the increased fluctuations of S pool caused by the release and deposition of S might further exacerbate S. alterniflora expansion in Cd contaminated coastal wetlands.

Does sulfur application continue to reduce cadmium accumulation and increase the seed yield of oilseed rape (Brassica napus L.) at the maturity stage?

Oilseed rape requires sulfur (S) fertilization. Cadmium (Cd) differs dramatically in agricultural soils. Rice-oilseed rape rotation distributes widely and contributes the majority of rapeseeds in Asian countries. It was reported that S metabolism was involved in Cd uptake in seedlings of oilseed rape, although the effects of S on Cd accumulation and seed yield at maturity are still unclear. We performed a pot experiment including two Cd rates (0.35 and 10.35 mg kg-1 , as low and high Cd soil) and four S levels (0, 30, 60 and 120 mg kg-1 ). The results showed that low S application (30 mg kg-1 ) resulted in two-fold higher seed-Cd concentration irrespective of soil Cd levels. The responsible mechanism might be that Cd translocation into rapeseeds was involved in sulfate transporters, which could be strongly expressed in shoots and roots when supplying sulfate under S-starvation conditions, but depressed under a S-sufficient environment. For high Cd soil, seed yield decreased by 36%, 48% and 72% at 30, 60 and 120 mg S kg-1 compared to non-S treatment, whereas there were no differences for low Cd soil. Antagonistic effects of S and Cd existed for seed yield according to structure equation model analysis. Oilseed rape can be grown in low-Cd fields as a safe food crop with high levels of sulfur fertilizers (>60 mg S kg-1 ). In high-Cd fields, oilseed rape is recommended as a Cd-remediation crop, and rapeseeds should only be used for industrial purposes and not for food. © 2021 Society of Chemical Industry.

Residual effects of sulfur application prior to oilseed rape cultivation on cadmium accumulation in brown rice under an oilseed rape–rice rotation pot experiment

We aimed to investigate how sulfur (S) application prior to oilseed rape cultivation influences the uptake of cadmium (Cd) by rice grown in low- and high-Cd soils. A pot experiment involving four S levels (0, 30, 60, 120 mg S kg−1) combined with two Cd rates (low and high—0.35 and 10.35 mg Cd kg−1, respectively) was conducted. Soil pore water during rice growth and plant tissues at maturity were analyzed. The soil pore water results indicated that S application decreased Cd solubility under submergence due to the S-induced increase of soil pH and the enhancement of sulfide formation in soil micropores. When S was applied at rates of 30, 60 and 120 mg S kg−1, brown rice Cd concentrations decreased by 18%, 18%, and 55% (p < 0.05) in the low-Cd soil but increased by 20%, 40%, and 40% in the high-Cd soil compared with those in the non-S treatment. The different effects of S on Cd accumulation in brown rice were related to Cd-induced oxidative stress in the rice plants. In low-Cd soils, a S-induced increase in phytochelatins in rice roots restricted and inhibited Cd translocation in brown rice. In high-Cd soils, the Cd-induced oxidative stress in rice plants weakened the protective effects of S, while highlighted the promotion of Cd uptake by S. Overall, S fertilizer is recommended for oilseed rape–rice rotations in low-Cd paddy fields. In high Cd-contaminated fields, oilseed rape–rice rotations are suitable for the simultaneous remediation by oilseed rape and production of rice without S fertilization.

Variation between hospital caesarean delivery rates when Robson's classification is considered: An observational study from a French perinatal network.

WHO has recommended using Robson's Ten Group Classification System (TGCS) to monitor and analyze CD rates. Its failure to take some maternal and organizational factors into account, however, could limit the interpretation of CD rate comparisons, because it may contribute to variations in hospital CD rates. To study the contribution of maternal socioeconomic and clinical characteristics and hospital organizational factors to the variation in CD rates when using Robson's ten-group classification system for CD rate comparisons. This prospective, observational, population-based study included all deliveries at a gestational age > 24 weeks at the 10 hospitals of the French MYPA perinatal network in the Paris area. CD rates were calculated for each TGCS group in each hospital. Interhospital variations in these rates were investigated with hierarchical logistic regression models to quantify the variation explained by differences in patient and hospital characteristics when the TGCS is considered. Variations in CD rates between hospitals were estimated with median odds ratios (MOR) to express interhospital variance on the standard odds ratio scale. The percentage of variation explained by TGCS and maternal and hospital characteristics was also calculated. The global CD rate was 24.0% (interhospital range: 17-32%). CD rates within each TGCS group differed significantly between hospitals (P<0.001). CD was significantly associated with maternal age (>40 years), severe preeclampsia, and two organizational factors: hospital status (private maternities) and the deliveries per staff member per 24 hours. The MOR in the empty model was 1.27 and did not change after taking the TGCS into account. Adding maternal characteristics and hospital organizational factors lowered the MOR to 1.14 and reduced the variation between hospital CD rates by 70%. Maternal characteristics and hospital factors are needed to address variation in CD rates among the TGCS groups. Therefore, comparisons of these rates that do not consider these factors should be interpreted carefully.

Cesarean delivery rates, hospital readiness and quality of clinical management in Ethiopia: national results from two cross-sectional emergency obstetric and newborn care assessments

BackgroundCesarean delivery (CD) rates have reached epidemic levels in many high and middle income countries while increasingly, low income countries are challenged both by high urban CD rates and high unmet need in rural areas. The managing authority of health care institutions often plays a role in these disparities. This paper shows changes between 2008 and 2016 in Ethiopian CD rates, readiness of hospitals to provide CD and quality of clinical care, while highlighting the role of hospital management authority.MethodsThis secondary data analysis draws from two national cross-sectional studies to assess emergency obstetric and newborn care. The sample includes 111 hospitals in 2008 and 316 hospitals in 2016, and 275 women whose CD chart was reviewed in 2008 and 568 in 2016. Descriptive statistics are used to describe our primary outcome measures: population- and institutional-based CD rates; hospital readiness to perform CD; quality of clinical management, including the relative size of Robson classification groups.ResultsThe national population CD rate increased from 2008 to 2016 (< 1 to 2.7%) as did all regional rates. Rates in 2016 ranged from 24% in urban settings to less than 1% in several rural regions. The institutional rate was 54% in private for-profit hospitals in 2016, up from 46% in 2008. Hospital readiness to perform CDs increased in public and private for-profit hospitals. Only half of the women whose charts were reviewed received uterotonics after delivery of the baby, but use of prophylactic antibiotics was high. Partograph use increased from 9 to 42% in public hospitals, but was negligible or declined elsewhere. In 2016, 40% of chart reviews from public hospitals were among low-risk nulliparous women (Robson groups 1&2).ConclusionsBetween 2008 and 2016, government increased the availability of CD services, improved public hospital readiness and some aspects of clinical quality. Strategies tailored to further reduce the high unmet need for CD and what appears to be an increasing number of unnecessary cesareans are discussed. Adherence to best practices and universal coverage of water and electricity will improve the quality of hospital services while the use of the Robson classification system may serve as a useful quality improvement tool.

Adsorption and Desorption Characteristics of Cadmium on Different Contaminated Paddy Soil Types: Kinetics, Isotherms, and the Effects of Soil Properties

The adsorption and desorption characteristics of cadmium (Cd) in uncontaminated soils have been investigated in numerous studies. However, similar studies on Cd-polluted soils from different sources, which exhibit complex physicochemical characteristics and internal interactions between Cd and the soil particles, are scarce. Therefore, in order to elucidate the adsorption and desorption characteristics of Cd in Cd polluted soils, six representative Cd-contaminated paddy soil samples were collected from farmlands in the vicinity of a steel plant (Soil 1), a smelter (Soil 2), a thermal power plant (Soil 3), two mining areas (Soil 4, the Dabaoshan mine, Shaoguan; Soil 5, a lead-zinc mine located at Lechang), and a paddy field irrigated with sewage at Zhongshan (Soil 6) in Guangdong Province, China. The analysis of the six soil samples showed that Cd adsorption fitted well to pseudo-second order as well as pseudo-first order kinetics; however, the pseudo-second order equation showed a better fit (R2 = 0.860–0.962), while Elovich and intraparticle kinetic models fitted the adsorption kinetics poorly. Further, the adsorption isotherms fitted well to both the Langmuir and Freundlich models, with the Freundlich model showing a better fit (R2 = 0.96–0.98). The following order was observed for the Cd(II) adsorption amount and rate: S5 &gt; S6 &gt; S1 &gt; S3 &gt; S2 &gt; S4; meanwhile, the desorption amount and rate followed the opposite trend. Furthermore, the pH and soil organic matter were identified as the soil characteristics with the most significant impact on the adsorption and desorption behaviors of Cd(II) in the Cd-polluted soils.

Effects of sulfur application on cadmium accumulation in brown rice under wheat-rice rotation

We investigated how sulfur (S) application prior to wheat cultivation under wheat-rice rotation influences the uptake of cadmium (Cd) in rice grown in low- and high-Cd soils. A pot experiment was conducted with four S levels (0, 30, 60, 120 mg S kg−1) and two Cd rates (low and high, 0.35 and 10.35 mg Cd kg−1) supplied to wheat. Part of the wheat straw was returned to the soil before planting rice, which was cultivated for 132 days. To explore the key mechanisms by which S application controlled Cd accumulation in brown rice, (1) soil pore water at the key growth stages was sampled, and dissolved Cd and S species concentrations were determined; (2) rice plant tissues (including iron plaque on the root surface) were sampled at maturity for Cd and S analysis. With increasing S level, Cd accumulation in brown rice peaked at 60 mg S kg−1, irrespective of soil Cd levels. For high-Cd soils, concentrations of Cd in brown rice increased by 57%, 228%, and 100% at 30, 60, and 120 mg S kg−1, respectively, compared with no S treatment. The increase in brown rice Cd by low S levels (0–60 mg kg−1) could be attributed to (1) the S-induced increase in soil pore water sulfate increasing the Cd influx into rice roots and (2) the S-induced increase in leaf S promoting Cd translocation into brown rice. However, brown rice Cd decreased at 120 mg S kg−1 due to (1) low Cd solubility at 120 mg S kg−1 and (2) root and leaf S uptake, which inhibited Cd uptake. Sulfur application to wheat crop increased the risk of Cd accumulation in brown rice. Thus, applying S-containing fertilizers to Cd-contaminated paddy soils is not recommended.

The potential of medicinal plant extracts in improving the phytoremediation capacity of Solanum nigrum L. for heavy metal contaminated soil

This study focused on the effects of eight medicinal plant extracts on Solanum nigrum L. potential to accumulate Cd and Pb from soil. These medicinal plants were common and relatively cheap. The eight 10% water extracts were made from the peel of Citrus reticulata Blanco (PCR), fruit of Phyllanthus emblica L. (FPE), root of Pueraria Lobata (Willd.) Ohwi (RPL), rhizome of Polygonatum sibiricum Red (RPS), root of Astragalus propinquus Schischkin (RAP), bud of Hemerocallis citrina Baroni (BHC), seed of Nelumbo nucifera Gaertn (SNN) and fruit of Prunus mume (Sieb.) Sieb.etZuce (FPM). The results showed that among all exposures, the treatment with FPE resulted in the significant increase (p < 0.05) of Cd and Pb concentration in shoots and roots of S. nigrum by 32.5% and 65.2% for Cd, and 38.7% and 39.6% for Pb. The biomasses of S. nigrum in all plant extract treatments were not significantly changed (p < 0.05) compared to the control (CK). The Cd and Pb extraction rates of S. nigrum in FPE treatment were increased respectively by 60.5% and 40.5% compared to CK. Though the treatment with EDTA significantly improved (p < 0.05) the concentration of Cd and Pb of S. nigrum, the Cd and Pb masses (ug plant−1) of S. nigrum did not show any significant difference compared to the CK due to the significant decrease in the shoot (20.4%) and root (22.0%) biomasses. The chelative role of FPE might be relation with its higher polyphenolic compounds. However, not sure if the contents of polyphenolic compounds was the only differences between FPE and other additives. Thus, some unknown organic matters might also play active role. This study provided valuable information on improving the phytoremediation potential of hyperaccumulator.

KOH modification effectively enhances the Cd and Pb adsorption performance of N-enriched biochar derived from waste chicken feathers.

Waste chicken feathers are the ideal precursor for the production of low-cost N-enriched biochar. KOH-modified N-enriched biochar (KNB) containing 15.92wt% N was successfully prepared using waste chicken feathers. The adsorption kinetics results showed that KNB had rapid Cd (2h) and Pb (1h) adsorption rates. The Cd and Pb adsorption capacities of KNB (the values of KF were 22.324 (Cd) and 119.654 (Pb) mg1-(1/n)·L1/n·g-1) were 7.07 and 26.52 times higher than those of the original biochar based on the adsorption isotherm results. The KNB was stable at pH 3-6 and had stronger co-adsorption capacities in double-ion systems. Based on the adsorption experiments and various characterization methods, we concluded that the primary Cd and Pb adsorption mechanisms of KNB involved electrostatic interactions, cation-π interactions, complexation, and K+ exchange. The precipitation mechanism could partially account for Pb adsorption but not for Cd adsorption. KOH modification enhanced the electronegativity of biochar and then increased the electrostatic attraction. Surface O- and N-containing functional groups were involved in Cd and Pb adsorption. Graphitic-N, oxidised-N, and OCO were the main active adsorption groups, the relative contents of which increased after KOH modification, thus increasing the Cd and Pb adsorption performance. Therefore, KNB can be used as a fast and highly efficient adsorption agent to remove Cd and Pb from wastewater containing either Cd and Pb or a combination of these two metals.

Are we preventing the primary cesarean delivery at the second stage of labor following ACOG-SMFM new guidelines? Retrospective cohort study

Objective In 2014, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal Fetal Medicine (SMFM) published an Obstetric Care Consensus for safe prevention of primary cesarean delivery. We aimed to assess whether these guidelines decreased the primary CD rate during the second stage of labor, in our department. Design, setting, and population A retrospective cohort study of all women reaching the second stage of labor, at term, in a single university-affiliated medical center between2010 and 2017. Methods We compared maternal and neonatal outcomes over three year’s periods:-pre-guidelines (2010–2013) vs. 2nd period – post-guidelines (2014–2017). The main outcome measures CD rate at 2ndstage of labor. Results The study included 11,464 women. The CD rate in the 2nd stage of labor has increased significantly from 4% to 5.9% in the post-guidelines period (OR 1.48, 95% CI 1.16–1.89, p = .001). After a sub-analysis of specific subgroups, and adjustment for confounders, the increase was solely observed in nulliparous women (aOR 1.418, 95% CI 1.067–1.885, p = .016). Furthermore, increased odds for vaginal operative delivery were observed in the multiparous women in the post-guidelines period (2.7% vs. 4.1%, p = .046). Conclusions The implementation of the new ACOG and SMFM guidelines was not associated with a change in the CD rate performed at the 2nd stage of labor in the whole study population. However, there was a rise in the CD rate performed at the 2nd stage in nulliparous women. Furthermore, there was an increase in operative deliveries in the whole study population, especially in multiparous women, without an apparent increase in other immediate adverse neonatal or maternal outcomes.

113 Advanced maternal age and its impact on the NTSV cesarean delivery rate

The nulliparous, term, singleton, vertex cesarean delivery (NTSV CD) rate is an established quality measure, with the national target set below 24% based on the Healthy People initiative. While advanced maternal age (AMA) is associated with a higher rate of cesarean delivery in general, its impact on the NTSV CD rate is unclear. Therefore, we sought to determine if AMA is associated with higher NTSV CD rates at our institution. Cohort study of women with NTSV pregnancies undergoing a trial of labor at our institution from August 2016 to August 2017. Those undergoing an elective cesarean delivery were excluded. The primary exposure was maternal age ≥35 years (AMA), and the primary outcome measure was the NTSV CD rate. Secondary outcomes were the NTSV CD rate by age category (<20, 20-24, 25-29, 30-34, 35-39 and ≥40 years). Confounders assessed included gestational age, BMI, race/ethnicity, insurance status and labor induction. We conducted analyses with Chi-squared tests and multivariable logistic regression, with α=0.05. We evaluated 2,862 women with NTSV pregnancies undergoing a trial of labor, of whom 931 (33%) were AMA and 498 (17%) had a cesarean delivery. Compared to the maternal age distribution of NTSV deliveries in the United States, our population was skewed towards more women with AMA (33% vs 10%, P<0.001), Table 1. At our institution, the NTSV CD rate was significantly higher in women ages 35 and over compared to those less than age 35 (24% vs 14%, P<0.001), Table 2. In addition, the NTSV CD rate increased with advancing maternal age category [<20 (0%), 20-24 (9%), 25-29 (13%), 30-34 (16%), 35-39 (22%) and ≥40 (31%), P<0.001]. The odds of NTSV CD was significantly greater in women ages 35 and over, even after adjustment for gestational age, BMI, race/ethnicity, insurance status and labor induction (aOR 1.8, 95% CI 1.5-2.2, P<0.001). The NTSV CD rate was significantly higher among women ages 35 and over undergoing a trial of labor at our institution. Maternal age distribution should be considered when assessing NTSV CD rates at individual institutions.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

272 Patient factors and impact on NTSV cesarean delivery rate among individual physicians

The nulliparous, term, singleton, vertex cesarean delivery (NTSV CD) rate is an established obstetric quality measure. Tracking NTSV CD rates of individual physicians may help identify outliers and drive change. However, patient factors may also contribute to physician NTSV CD rates. Therefore, we sought to determine if patient factors are associated with high versus low NTSV CD rates among individual physicians. Cohort study of women with NTSV pregnancies undergoing a trial of labor at our institution from August 2016 to August 2017. Those undergoing an elective cesarean delivery were excluded. The NTSV CD rates of individual physicians were determined over the 12-month study period. Those with a cumulative NTSV CD rate below the 50th percentile were classified as successful, and those above the 50th percentile unsuccessful. Patient factors were evaluated as predictors of successful NTSV CD rate, and included maternal age, BMI, race/ethnicity, gestational age and insurance status. We conducted analyses with Chi-squared tests and multivariable logistic regression, with α=0.05. We identified 2,862 women with NTSV pregnancies who were cared for by 78 individual physicians. The overall NTSV CD rate was 17.4% (498/2862). The 50th percentile for NTSV CD rate among individual physicians was 20%, and those below this rate were classified as successful (Figure 1). Compared to physicians with successful NTSV CD rates below 20%, those with higher rates had more patients who were Black (10% vs 7%, P=0.004), ≥35 years old (35% vs 31%, P=0.034) and undergoing induction (65% vs 61%, P=0.016). These factors remained significant after multivariable adjustment [aOR (95% CI): Black race, 1.5 (1.1-2.0); Age ≥35, 1.2 (1.0-1.4); and Induction, 1.2 (1.0-1.4)], (Table 1). Successful NTSV CD rates were not associated with BMI, insurance status, diabetes or hypertension. Individual physician NTSV CD rates were impacted by patient factors such as maternal age and Black race. Efforts should be devoted to decreasing NTSV CD rates in these populations.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A comparison of the concentrations of heavy metals in modern and medieval shells of swollen river mussels (Unio tumidus) from the Szczecin Lagoon, SW Baltic basin

The shells of mussels, live-collected bivalves or during archaeological excavations, can be used as bioindicators of current and historical levels of heavy metal contamination. In this study, we examined the shells of Unio tumidus, commonly found in the Baltic Sea region, and determined the concentrations of Zn, Cu, Fe, Pb, Ni, and Cd in samples from the 10th, 11th, and 21st century from the area of the Szczecin Lagoon. The average levels of heavy metals (in μg g−1 dry weight) in the shells from the Middle Ages were: 137.5 (Fe), 3.87 (Zn), 0.789 (Cu), 0.012 (Pb), 0.047 (Ni), and 0.0009 (Cd). Shells from the 21st century were significantly (P<0.05) more abundant in Fe, Cu, Ni, Pb, and Cd (rates of increase: 1.96×, 3.54×, 2.71×, 2.08×, and 3.55×, respectively) than shells from the Middle Ages. These results reflect contemporary anthropogenic pollution of the environment with heavy metals and confirm the possibility of using U. tumidus shells in the assessment of heavy metal pollution levels.

Gender Differences in Zinc and Copper Excretion in Response to Co-Exposure to Low Environmental Concentrations of Cadmium and Lead

Disruption of the homeostasis of zinc (Zn) and copper (Cu) has been associated with nephrotoxicity of cadmium (Cd). Herein, we report the results of a cross sectional analysis of urinary excretion of Zn, Cu, Cd and lead (Pb) in 392 Thais (mean age 33.6) living in an area of low-level environmental exposure to Cd and Pb, reflected by the respective median Cd and Pb excretion rates of 0.44 and 1.75 μg/g creatinine. Evidence for dysregulation of Zn and Cu homeostasis has emerged together with gender differentiated responses. In men, excretion rates for Zn and Cu were increased concomitantly, and their urinary Zn-to-Cu ratios were maintained. In women, only Cu excretion rose, causing a reduction in urinary Zn-to-Cu ratios. Only in women, urinary Zn-to-Cu ratios were associated with worse kidney function, assessed by estimated glomerular filtration rate (eGFR) (β = −7.76, p = 0.015). Only in men, a positive association was seen between eGFR and body iron stores, reflected by serum ferritin (β = 5.32, p = 0.030). Thus, co-exposure to Cd and Pb may disrupt the homeostasis of Zn and Cu more severely in women than men, while urinary Zn-to-Cu ratios and body iron stores can serve as predictors of an adverse effect of co-exposure to Cd and Pb.

Behaviors of cadmium in rhizosphere soils and its interaction with microbiome communities in phytoremediation

Phytoremediation of cadmium (Cd) contaminated soils by accumulators or hyperaccumulators has received considerable attention. However, there is still limited information about its migration, dynamic characteristics, and interaction with microbial communities in rhizosphere. In this study, the behaviors of Cd in rhizosphere soils in phytoremediation were carefully studied and illustrated. We find that the migration rate of Cd in rhizosphere is higher than the absorption rate of Cd by roots of plants, and Cd in near-rhizosphere moves sluggishly, and near-rhizosphere soils forms a mass pool of Cd for absorption by plants. Additionally, in tall fescue and Indian mustard treatments, shoot biomasses, total extracted Cd and migration rate of Cd in near-rhizosphere soils were comparable. It suggests that shoot biomasses of plants significantly affect their extraction of heavy metals from rhizosphere soils. Biomasses of bacteria significantly increased after phytoremediation, and structures of microbiome communities of soils after phytoremediation reassembled significantly. Furthermore, Indian mustard, even with relative lower root biomasses, could better reassembled the microbiome communities in rhizosphere than tall fescue which possesses a higher developed root system. In the end, analyses of functional microorganisms in rhizosphere soils provide new insights into biological and physiochemical roles of these populations in phytoremediation.

Unexpected Heavy Metal Pollution in Wetland Soils Along the Yarlung Tsangbo River in Tibet, China: Assessment and Source Apportionment

The Qinghai-Tibetan Plateau (QTP), as the third pole, has recently experienced unexpected heavy metal pollution. However, few were available on heavy metal pollution and source apportionment in regions near South Asia, where the economy is currently experiencing rapid development. This paper evaluated heavy metal pollution in wetland soils along the Yarlung Tsangbo River (YTR), the largest river in the QTP. Results indicated minor contamination levels of Cu, Pb, Zn, Hg, As, Mn, and Cr. However, Cd pollution was serious and was the main pollutant. Nemero synthesis index values (PN) were relatively high and ranged from 4.54 to 10.47 caused by high loading from Cd and Zn. Roughly 92% Pb, 89% Cr, and 89% Mn were from natural sources while 86% Cd and 61% Zn were from anthropogenic sources in wetland soils along the YTR. Differences in heavy metal contents and sedimentation rates were accentuated by the metal accumulation rates of each site. Cd, Zn, and Hg accumulation rates were estimated to 0.966 mg m−2 year−1, 0.187 g m−2 year−1, and 0.061 mg m−2 year−1 in the 1800s and increased to 5.351 mg m−2 year−1, 1.144 g m−2 year−1, and 0.263 mg m−2 year−1 in the 2000s, respectively. This implied unexpected heavy metal pollution in wetland soils along the YTR basin and more attention should be paid to avoid the risk of heavy metal pollution here.