Cellulose nanocrystals intercalated clay biocomposite for rapid Cr(VI) removal.

The application of bentonite (Bt) as an adsorbent for heavy metals has been limited due to its hydrophobicity and insufficient surface area. Herein, we present cellulose nanocrystal (CNC) modified Bt composite (CNC@Bt) with enhanced efficiency for Cr(VI) removal. CNC@Bt exhibited an increased specific surface area and a porous structure, while maintaining the original crystal structure of Bt. This was achieved through a synergistic function of ion exchange, hydrogen bonding, electrostatic interactions, and steric hindrance. The adsorption of Cr(VI) by CNC@Bt followed the pseudo-second-order kinetic and Langmuir isotherm adsorption model. Moreover, the process was endothermic and spontaneous. At an initial Cr(VI) concentration of 20 mg/L and pH = 4.0, 10 g/L CNC@Bt achieved a removal rate of 92.7%, and the adsorption capacity was 1.85 mg/g, significantly higher than bare Bt (37.9% and 0.76 mg/g). The removal efficiency remained consistently above 80% over a wide pH range, indicating the potential practical applicability of CNC@Bt. With its fast adsorption rate, pH adaptability, and stable performance, CNC@Bt presents promising prospects for the rapid treatment of Cr-contaminated wastewater.

Carbon fiber-based multichannel solid-contact potentiometric ion sensors for real-time sweat electrolyte monitoring.

Solid-contact ion-selective electrodes (SC-ISEs) feature miniaturization and integration that have gained extensive attention in non-invasive wearable sweat electrolyte sensors. The state-of-the-art wearable SC-ISEs mainly use polyethylene terephthalate, gold and carbon nanotube fibers as flexible substrates but suffer from uncomfortableness, high cost and biotoxicity. Herein, we report carbon fiber-based SC-ISEs to construct a four-channel wearable potentiometric sensor for sweat electrolytes monitoring (Na+/K+/pH/Cl-). The carbon fibers were extracted from commercial cloth, of which the starting point is addressing the cost and reproducibility issues for flexible SC-ISEs. The bare carbon fiber electrodes exhibited reversible voltammetric and stable impedance performances. Further fabricated SC-ISEs based on corresponding ion-selective membranes disclosed Nernstian sensitivity and anti-interface ability toward both ions and organic species in sweat. Significantly, these carbon fiber-based SC-ISEs revealed high reproducibility of standard potentials between normal and bending states. Finally, a textile-based sensor was integrated with a solid-contact reference electrode, which realized on-body sweat electrolytes analysis. The results displayed high accuracy compared with ex-situ tests by ion chromatography. This work highlights carbon fiber-based multichannel wearable potentiometric ion sensors with low cost, biocompatibility and reproducibility.

The relationship between TSH levels and clinical pregnancy outcomes for patients who undergo in vitro fertilization/intracytoplasmic sperm injection: a retrospective study.

Background: Thyroid dysfunction is linked with adverse pregnancy outcomes, an upper limit of a normal thyroid-stimulating hormone (TSH) threshold of 4.12-4.5 mIU/L should be considered for subclinical hypothyroidism in the infertile female population. Whereas, it's controversial whether or not the infertility thresholds for upper limit of TSH threshold of 2.5 mIU/L. In our study examines the correlation of optimal TSH levels and clinical pregnancy outcomes after fresh in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) embryo transfer cycles. Methods: Patients who underwent fresh IVF/ICSI embryo transfer cycles for the first time who presented between January 1, 2015 and December 31, 2017 at the Chongqing Institute of Reproductive and Genetic, Chongqing Health Center for Women and Children were enrolled. We excluded patients with ≥40 years, body mass index (BMI) ≤18 or ≥28 kg/m2, the man with severe oligoasthenospermia, women with poor ovarian reserve, and presence of endocrine disorders, uterine anomaly, sactosalpinx, abnormal thyroid function, preimplantation genetic diagnosis, and chromosomal abnormality or polymorphism. Baseline characteristics and clinical pregnancy outcomes were observed in our study. We detected between TSH levels and clinical pregnancy outcomes in patients undergoing IVF/ICSI by Receiver operating characteristic (ROC) curves and logical regression. Results: A total of 6,088 patients who undergo IVF/ICSI were included. We first detected that the live birth rate had a statistically significant difference when the TSH level was 3 mIU/L. With the TSH ≤3 mIU/L group having a higher live birth rate than the TSH >3 mIU/L group (51.79% vs. 47.89%, P=0.024), meanwhile no significant difference were revealed between the early miscarriage rate (12.54% vs. 14.97%, P=0.091) and early clinical pregnancy rate (59.21% vs. 56.32%, P=0.114). There were no differences in pregnancy outcomes when the TSH threshold was at 3.5 or 4 mIU/L and no association was detected between TSH levels and clinical pregnancy outcomes in patients undergoing IVF/ICSI by ROC curves and logical regression. Conclusions: Patients undergoing IVF/ICSI with a serum TSH level ≤3 mIU/L may have a higher live birth rate rather than ≤2.5 or ≤4 mIU/L.

Improvement of sludge dewaterability by ammonium sulfate and the potential reuse of sludge as nitrogen fertilizer.

A novel method to enhance sludge dewaterability with ammonium sulfate ((NH4)2SO4) was proposed, and the potential reuse of dewatered sludge cake and filtrate as nitrogen fertilizers was evaluated. Compared with raw sludge, 87.91% reduction of capillary suction time (CST) and 88.02% reduction of specific resistance to filtration (SRF) after adding 80% (m/m) (NH4)2SO4 were achieved, with 38.49% of protein precipitated simultaneously. The (NH4)2SO4 dose destroyed cell membrane, resulting in the release of intracellular water by converting bound water into free water, thus enhancing sludge dewaterability. In the solid phase, the content of protein-N increased, and larger protein aggregates were formed. The (NH4)2SO4 dose destroyed the hydration shell, making proteins to exhibit hydrophobic interactions, and to be aggregated, and precipitated from the liquid phase. When incubated Pennisetum alopecuroides L. with the dewatered sludge cake and filtrate after dewatering and conditioning with (NH4)2SO4, the germination rate of grass seed and shoot lengths both increased while compared with those incubated with dewatered sludge cake and filtrate of the raw sludge. This study might provide insights into sustainable sludge treatment by integrating sludge dewatering and the potential reuse of dewatered sludge cake and filtrate as nitrogen fertilizer via treatment with (NH4)2SO4.

Facile and Cost-Effective Approach for Copper Recovery from Waste Printed Circuit Boards via a Sequential Mechanochemical/Leaching/Recrystallization Process.

The recovery of copper (Cu0) from waste printed circuit boards (WPCBs) is a great challenge as a result of its heterogeneous structural properties, with a mixture of metals, epoxy resin, and fiberglass. In this study, a three-step sequential process, including mechanochemical processing, water leaching, and recrystallization, for Cu0 recovery from WPCB powder is reported. Potassium persulfate (K2S2O8), instead of acid/alkali reagents, was employed as the sole reagent in the cupric sulfate (CuSO4) regeneration process. Complete oxidation of Cu0 in the WPCBs to copper oxide (CuO) and CuSO4 was first achieved during mechanochemical processing with K2S2O8 as the solid oxidant, and the K2S2O8 was simultaneously converted to sulfate compounds [K3H(SO4)2] via a solid-solid reaction with epoxy resin (C nH mO y) as the hydrogen donator under mechanical force. The rapid leaching of Cu species in the forms of CuO and CuSO4 was therefore easily realized with pure water as a nontoxic leaching reagent. The kinetics of the leaching process of Cu species was confirmed to follow the shrinking nucleus model controlled by solid-film diffusion. Finally, CuSO4·5H2O was successfully separated by cooling crystallization of the hot saturated solution of sulfate salt [K2Cu(SO4)2·6H2O]. An efficient conversion of Cu0 to CuSO4·5H2O product, for WPCB recycling, was therefore established.

[Intrauterine injection of human chorionic gonadotropin improves pregnancy outcome in patients with repeated implantation failure in frozen-thawed embryo transfer].

OBJECTIVE: To investigate whether intrauterine injection of human chorionic gonadotropin (hCG) before the embryo transfer in a frozen-thawed transfer cycle can improve the pregnancy outcome in the patients with repeated implantation failure (RIF).
 Methods: Prospective randomized-controlled trial was adopted. A total of 140 patients, who underwent thawed embryo transplantation and were in line with the diagnosis of RIF, were included. Other patients with some factors, such as uterine malformation, postoperative uterine cavity sticking, tubal effusion, endocrine diseases and endometriosis, were excluded. The patients were randomly divided into 2 groups through the computer random number table: an hCG intrauterine perfusion group and a control group. There was no significant difference in the age, the estradiol level, the number of transplanted embryos, the number of optimal embryos, and the thickness of the endometrium before transplantation between the 2 group (all P>0.05). The hCG+G2 fluid and the G2 fluid were prepared on the day of embryo transfer, and 40 µL of which was injected at an intrauterine site at 3 minutes before embryo transfer in the hCG intrauterine perfusion group and the control group, respectively. The clinical pregnancy rate and implantation rate in the 2 groups were compared.
 Results: The implantation rate and the clinical pregnancy rate in the hCG intrauterine perfusion group were higher than those in the control group (both P<0.05).
 Conclusion: The intrauterine injection of hCG can improve the implantation rate and pregnancy rate in cryopreserved embryo transfer in patients with RIF.

Improving bromine fixation in co-pyrolysis of non-metallic fractions of waste printed circuit boards with Bayer red mud.

A method to improve bromine fixation by co-pyrolysis of non-metallic fractions (NMFs) of waste printed circuit boards (WPCBs) with Bayer red mud (RM) has been developed. More than 78.59 wt% of bromine was fixed into the solid residues with an addition of 15 wt% RM after co-pyrolysis at 500 °C, comparing with 36.42 wt% without the RM addition. Metal oxides (Fe2O3, Al2O3, TiO2, and Na2O, etc.) in the RM contributed significantly to the bromine fixation. The bromine fixation percentages were 62.94, 65.05, 47.24, and 49.05 wt% with an individual addition of 15 wt% Fe2O3, Na2O, Al2O3, and TiO2, respectively. Metal oxides in the RM showed synergistic effects on the bromine fixation, and this can be attributed to the secondary reaction of Na2O and bromine decomposed from FeBr3. The mechanisms of bromine fixation by RM are formation of Br-M (M: Fe, Al, Ti, and Na) and OH bonds generated from the direct elimination and a two-step of dissociative adsorption and ß-H elimination reactions between metal oxides and bromide.

Meta-analysis identifies candidate key genes in endometrium as predictive biomarkers for clinical pregnancy in IVF.

Genetic factors in endometrium are likely to be involved in the embryo implantation failure (IF), one of the major limiting factors in the success of in vitro fertilization (IVF). In this study, we aimed to identify critical genes from the transcriptional profile for the establishment of the endometrial receptivity which supporting the normal pregnancy. Three GEO datasets, including 12 samples of IF and 12 samples of controls, were used for the meta-analysis. We identified 182 different expression genes (DEGs) by comparing IF with controls and present here the successful clustering according to sample type, not by the origin. The gene ontology (GO) enriched analysis demonstrated the significant downregulation in activation and regulation of inflammatory and immune response in IF patients. Furthermore, network analysis of down-regulated genes identified the significant hub genes containing GADD45A (growth arrest and DNA damage inducible alpha, Degree = 77), GZMB (granzyme B, Degree = 38) and NLRP2 (NLR family pyrin domain containing 2, Degree = 37). The lower expression of NLRP2, related to inflammatory responses with the most degree in the network, was validatied by other GEO data. Besides, it was confirmed that the NLRP2 could act as a predictor for pregnancy after IVF (AUC = 87.93%; sensitivity, 60.00%; specificity, 91.30% ). Our meta-analysis will help us to better understand the molecular regulation of endometrial receptivity, and guiding further line of treatment for IF during IVF.

Migration and distribution of sodium ions and organic matters during electro-dewatering of waste activated sludge at different dosages of sodium sulfate.

In this study, the influence of Na2SO4 on electro-dewatering (EDW) of waste activated sludge (WAS) was investigated. The highest water removal efficiency of 42.5% was achieved at the optimum Na2SO4 dosage of 12.5 g kg-1 DS during EDW process at a constant voltage of 20 V. The migration and distribution of water, organic matters and Na+ at different Na2SO4 dosages were investigated through layered experiments. The results indicated the entire EDW process followed the S curve model, and it can be divided into three stages: (1) initial desalination stage: at the initial few min of EDW process, the rate of electroosmosis was extremely slow while electromigration of ions like Na+ was intense, and the electromigration was more obvious with increased Na2SO4 dosage; (2) dewatering stage: the dewatering efficiency increased dramatically via electroosmosis; (3) the dewaterability limit stage: the maximum value of dewatering efficiency has been achieved, while the water removal efficiency and dry solids content remained constant. During the EDW process, the possible electrolysis resulted in a pH gradient in the sludge cake. With the addition of Na2SO4 in the EDW, the pH gradient was intensified, and the migration rate of organic matters moving from cathode to anode increased while compared with the raw WAS. This study provided insights into the mechanism of EDW process at different dosages of Na2SO4.

Synergistic effect of water content and composite conditioner of Fenton's reagent combined with red mud on the enhanced hydrogen production from sludge pyrolysis.

This study investigated the synergistic effect of water content and a composite conditioner of Fenton's reagent combined with red mud (Fenton-RM) on the pyrolytic products (fuel gas, tar, and solid char) of deep-dewatered sludge. The catalytic effect of metal oxides in Fenton-RM could be promoted by the presence of water during sludge pyrolysis, showing higher gas yield with increased water content. Maximum gas outputs of the deep-dewatered sludge conditioned with Fenton-RM (S-Fenton-RM) and the conventional dewatered sludge conditioned with polyacrylamide (S-PAM), both appeared at 900 °C with a water content of 65 wt%, and were 0.257 and 0.189 L/g dry solid (DS), respectively. At the same temperature and with the same water content, the hydrogen (H2) yields of the S-Fenton-RM samples were always higher than those of the S-PAM samples. At 900 °C, the maximum H2 yield of the S-Fenton-RM samples was 0.102 L/g DS, which was 85.5% higher than that of the S-PAM samples. The results indicated that water in the wet sludge provided the steam atmosphere for pyrolysis, and the water vapor then involved in secondary cracking reformation of tar and char gasification reactions, which would be catalyzed by the presence of metal oxides in the Fenton-RM conditioner, thus increasing the yield of fuel gas, especially hydrogen. The H2 production cost from the S-Fenton-RM system is less than that from the S-PAM system. The results suggest that pyrolysis of the wet deep-dewatered sludge conditioned with Fenton-RM is an economical and promising alternative for sewage sludge dewatering and disposal/reuse.