Insights into the Mechanism of Efficient Cr(VI) Removal from Aqueous Solution by Iron-Rich Wheat Straw Hydrochar: Coupling DFT Calculation with Experiments.

Agricultural solid waste has become one of the raw materials for hydrothermal carbon production, promoting resource utilization. This study synthesized two types of ball-milling carbons (Fe-MHBC vs MHBC) with and without FeCl3 modification using wheat straw hydrochars. Cr(VI) adsorption on these two types of ball-milling carbons was investigated. According to Langmuir's maximum adsorption capacity analysis, Fe-MHBC had a capacity of 116.29 mg g-1. The thermodynamic analysis based on isothermal adsorption reveals the spontaneous process of the reaction between the two materials. The adsorption of Cr(VI) on Fe-MHBC exhibited excellent agreement with the pseudo-second-order kinetics model. Furthermore, X-ray photoelectron spectroscopy analysis showed that Fe(II) in the material reduced Cr(VI) when it participated in the reaction. The acidic conditions facilitate the elimination of Cr(VI). The Fe-MHBC has a higher zeta potential, which enhances the electrostatic attraction of Cr(VI) particles. Even with a starting pH of 10, the removal rate can be consistently maintained at over 64%. The adsorption of Cr(VI) was inhibited by various anions and higher ion concentrations. Density functional theory demonstrates that the presence of Fe enhances the adsorption capacity and electron transfer flux of Cr(VI). Fe-MHBC effectively eliminates Cr(VI) by the process of electrostatic adsorption, redox, and complexation reactions. This study demonstrated that hydrochar materials modified by FeCl3 through a ball-milling process show considerable potential as effective adsorbents in the treatment of Cr(VI) pollution, offering a viable and environmentally friendly solution for mitigating this prevalent environmental issue.

Fabrication of Iron-Containing Biochar by One-Step Ball Milling for Cr(VI) and Tetracycline Removal from Wastewater.

Simple ball milling technology can simultaneously improve the adsorption performance of adsorbents for heavy metals and organic pollutants and has attracted increasing attention. Iron-modified biochar (Fe@MBC) was prepared by one-step ball milling, and the characterization results proved that FeCl3 was successfully loaded on biochar. The removal rates of Cr(VI) and tetracycline hydrochloride (TC) by Fe@MBC were increased by 88.27% and 82.64% compared with BC. The average pore size, oxygen-containing functional groups and graphitization degree of Fe@MBC are higher than those of BC, which is more conducive to promoting adsorption. The adsorption isotherms show that the adsorption of Cr(VI) and TC on the Fe@MBC surface conforms to the Langmuir type of single-layer adsorption and the Freundlich model of multilayer adsorption, respectively. The maximum adsorption capacities of Cr(VI) and TC are 25.46 and 66.91 mg·g-1, respectively. Kinetic experiments show that the adsorption process is more consistent with the pseudo-second-order model of chemical adsorption. The adsorption process of Cr(VI) and TC on the Fe@MBC surface is a spontaneous endothermic process that becomes more obvious as the temperature increases. The increase in solution pH has a significant impact on the removal rate of Fe@MBC. When the pH value increased from 3 to 11, the adsorption rates decreased by 53.74% and 17.16%, respectively. The presence of PO43-, CO32-, K+, and Cu2+ significantly affects the adsorption of TC by Fe@MBC, and PO43- and CO32- also affect the adsorption of Cr(VI). Mechanistic studies show that ion exchange, electrostatic interaction, pore filling, and hydrogen bonding contribute to the removal of Cr(VI) and TC by Fe@MBC. The removal mechanism of Cr(VI) also involves complexation and redox reactions, and the removal mechanism of TC involves π-π bonds and van der Waals forces. The results show that Fe@MBC is a green and efficient adsorbent.

Remarkable synergy between sawdust biochar and attapulgite/diatomite after co-ball milling to adsorb methylene blue.

Biochar has been recognized as a promising sustainable adsorbent for removing pollutants from wastewater. In this study, two natural minerals, attapulgite (ATP) and diatomite (DE) were co-ball milled with sawdust biochar (pyrolyzed at 600 °C for 2 h) at ratios of 10-40% (w/w) and examined the ability of methylene blue (MB) to be removed from aqueous solutions by them. All the mineral-biochar composites sorbed more MB than both ball milled biochar (MBC) and ball milled mineral alone, indicating there was a positive synergy in co-ball milling biochar with these minerals. The 10% (w/w) composites of ATP:BC (MABC10%) and DE:BC (MDBC10%) had the greatest MB maximum adsorption capacities (modeled by Langmuir isotherm modeling) and were 2.7 and 2.3 times that of MBC, respectively. The adsorption capacities of MABC10% and MDBA10% were 183.0 mg g-1 and 155.0 mg g-1 at adsorption equilibrium, respectively. These improvements can be owing to the greater content of oxygen-containing functional groups and higher cation exchange capacity of the MABC10% and MDBC10% composites. In addition, the characterization results also reveal that pore filling, π-π stacking interactions, hydrogen bonding of hydrophilic functional groups, and electrostatic adsorption of oxygen-containing functional groups also contribute prominently to the adsorption of MB. This, along with the greater MB adsorption at higher pH and ionic strengths, suggests the roles in MB adsorption was an electrostatic interaction and an ion exchange mechanism. These results demonstrate that mineral-biochar composites prepared by co-ball milling treatment were promising sorbents of ionic contaminants for environmental applications.

Increasing dominant follicular proportion negatively associated with good clinical outcomes in normal ovarian responders using the depot GnRH agonist protocol: a large-sample retrospective analysis.

BACKGROUND: Currently, there is no universal criteria for the trigger time of controlled ovarian hyperstimulation (COH), especially with the emerging depot GnRH agonist protocol. It is challenging to explore an indicator that is representative of target follicle cohort development as an alternative to the conventional approach of determining the trigger time based on a few leading follicles. METHODS: This was a large-sample retrospective analysis. Between January 2016 and January 2020, 1,925 young normal ovarian responders who underwent their first in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycle using the depot GnRH agonist protocol were included. They were divided into three groups based on the dominant follicular proportion (DFP, defined as the ratio of ≥ 18 mm dominant follicles/ ≥ 14 mm large follicles on the human chorionic gonadotropin (HCG) day; Group A: < 30%; Group B: 30%-60%; and Group C: ≥ 60%). The binary logistic regression and multivariate linear regression were used to assess whether the DFP was associated with clinical pregnancy, the number of frozen blastocysts, the blastocyst formation rate, and the low number of frozen blastocysts. RESULTS: The logistic regression analysis showed that compared with Group A, the odds ratio (OR) for clinical pregnancy was 1.345 in Group B (P = 0.023), and there was no statistical difference between Group C and Group A (P = 0.216). The multivariate linear regression analysis showed that DFP was negatively associated with the number of frozen blastocysts (ß ± SE: Group B vs. Group A = - 0.319 ± 0.115, P = 0.006; Group C vs. Group A = - 0.432 ± 0.154, P = 0.005) as well as the blastocyst formation rate (ß ± SE: Group B vs. Group A = - 0.035 ± 0.016, P = 0.031; Group C vs. Group A = - 0.039 ± 0.021, P = 0.067). Furthermore, the OR for the low number of frozen blastocysts was 1.312 in Group B (P = 0.039) and 1.417 in Group C (P = 0.041) compared to Group A. CONCLUSIONS: For young normal ovarian responders using the depot GnRH agonist protocol, increasing DFP might reduce the developmental potential of oocytes and reduce the number of available blastocysts, and this might result in a lower cumulative pregnancy rate. However, further confirmation using strict prospective randomised controlled studies is required.

Deep sequencing shows that accumulation of potentially pathogenic mtDNA mutations rather than mtDNA copy numbers may be associated with early embryonic loss.

PURPOSE: To explore the relationship between mitochondrial DNA quantity and heteroplasmy and early embryonic loss. METHODS: A total of 150 villous samples from patients with spontaneous abortion (SA, n = 75) or induced abortion (IA, n = 75) were collected. qPCR and next-generation sequencing (NGS) were used to test mitochondrial DNA quantity and heteroplasmy. Missense mutations with a CADD score > 15 and heteroplasmy ≥ 70% were defined as potentially pathogenic mutations. RESULTS: With respect to mitochondrial DNA copy numbers, there was no significant difference between the SA and IA groups (median (IQR), 566 (397-791) vs. 614 (457-739); P = 0.768) or between the euploid and aneuploid groups (median (IQR), 516 (345-730) vs. 599 (423-839); P = 0.107). mtDNA copy numbers were not associated with spontaneous abortion using logistic regression analysis (P = 0.196, 95% CI 1.000-1.001). In addition, more patients harbored possibly pathogenic mtDNA mutations in their chorionic villi in the SA group (70.7%, 53/75) compared with the IA group (54.7%, 41/75; P < 0.05). However, there was no statistical difference between the euploid (80%, 24/30) and aneuploid groups (64.4%, 29/45; p = 0.147). CONCLUSION: Early embryonic loss and the formation of aneuploidy were not related to mtDNA copy number. Patients with spontaneous abortion were more likely to have possibly pathogenic mutations in their mtDNA, and this may assist in purifying pathogenic mtDNA. However, whether the accumulation of these potentially morbific mtDNA mutations caused early embryonic loss requires further investigation.

The effect of serum vitamin D levels in couples on embryo development and clinical outcomes.

RESEARCH QUESTION: Do serum vitamin D levels in men and women undergoing IVF/intracytoplasmic sperm injection (ICSI) affect embryo development and clinical outcomes? DESIGN: A large retrospective observational cohort study conducted between March 2016 and March 2017; plasma 25-OHD levels were measured before ovarian stimulation in couples undergoing IVF/ICSI (including 1883 women and 1720 men). RESULTS: Women were divided into four groups in terms of serum 25-OHD quartiles: <14.8 ng/ml (Q1), 14.8-19.6 ng/ml (Q2), 19.7-24.7 ng/ml (Q3) or >24.7 ng/ml (Q4). Statistically significant differences in top-quality embryo rates were found among different groups on Day 3 (P = 0.016) but not on Day 2 or Day 5/6. Specifically, the top-quality embryo rate on Day 3 was highest in Q2, a statistically significant difference compared with Q3 (P = 0.014). The multiple linear regression showed that serum 25-OHD levels in women were not significantly related to top-quality embryo rates on Day 2, Day 3 or Day 5/6. There were no differences in implantation, clinical pregnancy, miscarriage and live birth rates among the groups. Logistic regression revealed that there were no significant differences in the success of clinical pregnancy. In men, no significant association was found between vitamin D status and embryo development or clinical outcomes. CONCLUSIONS: In neither men nor women were vitamin D levels associated with embryo development in cleavage (Day 2 and Day 3) and blastocyst (Day 5/6) stage and clinical outcomes. This may be because the threshold of vitamin D affecting the reproductive process is relatively low; a multicentre study in a high-latitude region is needed.

CDKN1C (P57): one of the determinants of human endometrial stromal cell decidualization.

Decidualization is regulated by crosstalk of progesterone and the cAMP pathway. It involves extensive reprogramming of gene expression and includes a wide range of functions. To investigate how cell cycle regulatory genes drive the human endometrial stromal cell (ESC) exit cell cycle and enter differentiation, primary cultured ESC was treated with 8-Br-cAMP and MPA and cell cycle distribution was investigated by flow cytometry. High-throughput cell cycle regulatory gene expression was also studied by microarray. To validate the results of microarray chip, immunohistochemistry and semi-quantitative method of optical density were used to analyze the expression of cell cycle regulator proteins in proliferative phase of endometrium (n = 6) and early pregnancy decidua (n = 6). In addition, we selected cyclin-dependent kinase inhibitor 1c (CDKN1C, also known as P57) and cyclin-dependent kinase inhibitor 2b (CDKN2B, also known as P15) in order to study their role in the process of decidualization by the RNAi method. ESC was arrested at G0/G1 checkpoints during decidualization. Cell cycle regulatory genes P57 and P15 were upregulated, while cyclin D1 (CCND1), cyclin-dependent kinase 2 (CDK2), and cell division cycle protein 2 homolog (CDC2) were downregulated during ESC differentiation both in vitro and vivo. P57 siRNA impaired ESC decidualization and caused different morphological and ultrastructural changes as well as a relatively low secretion of prolactin, but P15 siRNA had no effects. We concluded that P15, CCND1, CDK2, and CDC2 may participate in ESC withdraw from the cell cycle and go into differentiation both in vitro and in vivo. P57 is one of the key determinants of ESC differentiation due to its effect on the cell cycle distribution, but its association with the decidua-specific transcription factor needs further investigation.

Long-term effects of methamphetamine exposure in adolescent mice on the future ovarian reserve in adulthood.

Currently, there is an increasing prevalence of adolescent exposure to methamphetamine (MA). However, there is a paucity of information concerning the long-term impact of early exposure to MA upon female fertility and ovarian reserve. The aim of this study was to investigate the effect of long-term MA exposure in adolescents on their ovarian reserve in adulthood. Adolescent mice received intraperitoneal injections of MA (5mg/kg, three times per week) or saline from the 21st postnatal day for an 8 week period. Morphological, histological, biochemical, hormonal and ethological parameters were evaluated. An impaired ovarian reserve and vitality was found in the group treated with MA, manifesting in morphological-apparent mitochondrial damage, an activated apoptosis pathway in the ovarian tissue, a downward expression of ovarian anti-Mullerian hormone (AMH), a decreased number of primordial and growing follicles, an increased number of atretic follicles, and a depressed secretion of AMH, estradiol and progesterone from granulosa cells. However, no significant difference was noticed regarding the estrous cycle, the mating ability and the fertility outcome in the reproductive age of the mice after a period of non-medication. The present results confirmed that a long term exposure to methamphetamine in adolescent mice does have an adverse impact on their ovarian reserve, which indicates that such an early abuse of MA might influence the fertility lifespan of the female mouse.

Could pretreatment with oral contraceptives before pituitary down regulation reduce the incidence of ovarian hyperstimulation syndrome in the IVF/ICSI procedure?

The long gonadotrophin releasing-hormone agonists (GnRH-a) protocol of pituitary down regulation was widely used in controlled ovarian hyperstimulation (COH). Some clinicians prefer to use one cycle of oral contraceptives (OC) pretreatment before the traditional long GnRH-a protocol. This study was aimed to investigate whether such pretreatment could reduce the incidence of ovarian hyperstimulation syndrome (OHSS) for patients with different ovarian responses in IVF/ICSI treatment. Participants undergoing IVF/ICSI treatment with long GnRH-a protocol of pituitary down regulation in luteal phase were recruited by their potential risk of OHSS into one group of suspected high responders (227 participants) and the other group of suspected normal responders (665 participants). As for the suspected high responders, pretreatment with OC could lower the serum LH level, LH/FSH ratio and E2 level right after 14 days of pituitary down regulation. It could also lower the serum E2 level before oocytes retrieval and the count of oocytes collected. The incidence of severe OHSS was also significantly decreased. Such effect of OC on hormone profile, follicular dynamics and incidence of OHSS was not discovered in the group of suspected normal responders.

The effect of accompanying dominant follicle development/ovulation on the outcomes of frozen-thawed blastocyst transfer in HRT cycle.

The artificial regime was widespread used in frozen-thawed embryo transfer (FET). Some researchers asserted that if dominant follicles developed or ovulation occurred in hormone replacement FET cycles, this cycle should be cancelled because the fitting timing of transfer was hard to determine. In this study, we compared the difference between the outcome of frozen-thawed blastula transfer in hormone replacement treatment cycle (HRT) with or without dominant follicle development/ovulation. A total of 171 cases of frozen-thawed blastula transferred successfully in HRT cycle were retrospectively analyzed. Patients were divided into three groups according to dominant follicle development, ovulation or not: Group A, cycles without dominant follicle developing. Group B, cycles with dominant follicle developing but without ovulation. Group C, ovulated cycles. The results showed that there was no significant difference in the pregnancy rates or other parameters among the three groups, but the abortion rate was higher in group C than those of other two groups. To conclude, dominant follicle development/ovulation was not the necessary indication to cancel transfer cycles in HRT cycles, and our cautious decision would save many valuable cycles.