Self-catalytic decomplexation of Cu-TEPA and simultaneous recovery of Cu by an electrochemical ozone production system using heterojunction Ni-Sb-SnO2 anode.

Heavy metal complexes from the industrial wastewater induce risks for the humans and ecosystems, yet are valuable metal resources. For energy saving and emission reduction goals, the simultaneous decomplexation and recovery of metal resources is the ideal disposal of wastewater with heavy metal complexes. Herein, a self-catalytic decomplexation scheme is developed via an electrochemical ozone production (EOP) system to achieve efficient decomplexation and Cu recovery. The EOP system could achieve 94.36% decomplexation of Cu-TEPA, which is a typical complex in catalyst industrial wastewater, and 86.52% recovery of Cu within 60 min at a current density of 10 mA/cm2. The O3 and •OH generated at the anode would first attack Cu-TEPA to produce Cu-organic nitrogen intermediates, which further catalyze O3 to generate •OH, thus self-enhancing the decomposition process in the EOP system. The released Cu2+ was gradually reduced to Cu+ and finally deposited as Cu2O and Cu to the stainless steel cathode. The technological feasibility was confirmed with other Cu-complexes such as Cu-EDTA and Cu-citrate, and the actual Cu-TEPA-containing industrial wastewater. The results provide new insights regarding the application of EOP in the simultaneous treatment of heavy metal complex wastewater and resource recovery.

Inactivation of Escherichia Coli by mixed-valent nanoparticles in-situ generated during Fe electrocoagulation.

Electrocoagulation (EC) is promising for the removal of chemical and microbial contaminants. Although the removal of pathogens from wastewater is efficient by conventional Fe-EC in the presence of dissolved oxygen (DO), the non-inactivated pathogens in the sediment still have a risk. Herein, the inactivation of Escherichia coli (E. coli) with the mixed-valent iron nanoparticles, magnetite and green rust (GR), in-situ generated from Fe-EC process in the absence of DO was investigated. The inactivation efficiency was significantly higher with magnetite (4.7 log cells) and GR (3.2 log cells) compared with FeOOH (0.7-1.7 log cells) generated at 50 mA in 10 min. The unstable in-situ generated magnetite with positive charges was prone to adsorb onto E. coli, damaging the cell membrane, inactivating the bacteria. The unstable in-situ generated GR was prone to coagulate with E. coli, delivering Fe2+ into the cell and inducing the generation of endogenous ROS, inactivating the bacteria. Fe-EC in the absence of DO was proved to be efficient for the inactivation of E. coli (4.2-4.3 log cells) in real wastewater. These findings identified the ignored inactivation effect and mechanism of E. coli with magnetite and GR generated in situ from Fe-EC process, which will provide theoretical support for real applications.

Sperm retrieval rate and patient factors in azoospermia factor c microdeletion azoospermia: a systematic review.

OBJECTIVE: To reveal the overall sperm retrieval rate (SRR) and range in patients with azoospermia factor c (AZFc) microdeletion azoospermia by microdissection testicular sperm extraction (mTESE) and discuss the differences of preoperative patient factors among studies with various SRRs. PATIENTS AND METHODS: We searched PubMed, Web of Science and Embase until February 2023. All studies reporting SRRs by mTESE and required parameters of patients with AZFc microdeletions were included. The primary outcome was the SRR and, if available, the pregnancy rate (PR) and live-birth rate (LBR) after intracytoplasmic sperm injection were also investigated as secondary outcomes. RESULTS: Eventually 11 cohort studies were included in this review. A total number of 441 patients underwent mTESE and in 275 of them sperm was obtained, reaching an overall SRR of 62.4%. The SRRs among studies had a wide range from 25.0% to 85.7%. The studies reporting higher SRRs generally had older mean ages, and higher follicle-stimulating hormone and testosterone levels. Only four studies provided practical data on pregnancies and live-born children of patients with AZFc microdeletions, so the overall PR and LBR were unavailable. CONCLUSIONS: The overall SRR of patients with AZFc microdeletion azoospermia was 62.4%. The effect of patient factors in SR needs further evidence in future work.

Enhanced photoelectrocatalytic oxidation of hypophosphite and simultaneous recovery of metallic nickel via carbon aerogel cathode.

Carbon aerogel (CA) cathode was adopted to an undivided-chamber photoelectrocatalytic system with TiO2 nanotube arrays (TNA) photoanode to enhance the oxidation of hypophosphite (H2PO2-) and simultaneous recovery of metallic nickel (Ni). Both the efficiencies of H2PO2- oxidation and Ni recovery were significantly enhanced after replacing Ti or carbon fiber paper cathode with CA cathode. With 1.0 mM H2PO2- and 1.0 mM Ni2+, the ratio of PO43- production increased from ∼41% or ∼54% to ∼100%, and the ratio of Ni recovery increased from ∼20% or ∼ 37% to ∼93% within 180 min at 3.0 V. H2PO2- was finally oxidized to PO43- by •OH radicals, which was speculated to be generated from UV/H2O2 and bound on TNA photoanode. Meanwhile, Ni2+ was eventually electro-reduced to metallic Ni by a two-electron reduction reaction. The efficiencies of H2PO2- oxidation and Ni recovery were favored at higher cell voltage, faintly acid conditions and larger H2PO2- concentration. The stability of this system exhibited that the ratio of PO43- production increased significantly in each cycle, which was attributed to the increase of H2O2 in-situ-generation via CA cathode caused by deposition of metallic Ni. Finally, the treatment of actual electroless nickel plating effluents was demonstrated.

Nickel phosphide on Ni foam as anode and peroxymonosulfate as the chemical oxidizer for effective direct urea fuel cell.

The direct urea fuel cell (DUFC) is a low cost and competitive approach for contemporaneous urine or urea-contaminated wastewater treatment and electricity generation. However, the lack of efficient urea oxidation reaction (UOR) electrocatalysts and suitable electron acceptors remains a challenge for practical applications. Here, we developed a DUFC system using Ni2P@Ni foam as the anode and peroxymonosulfate (PMS) as the chemical oxidizers. The Ni2P@Ni foam anode showed a high oxidation activity for UOR with an onset potential of 0.30 V vs. Ag/AgCl and Tafel slope of 34.4 mV/dec. PMS with high theoretical potential improved the cell voltage to 1.43 V. A power density of DUFC up to 4.91 mW/cm2 was achieved using PMS at room temperature, which was approximately twice as high as using H2O2 (2.38 mW/cm2). NiII/NiIII was the redox active species on the Ni2P anode in the DUFC process, and NiII was electrochemically oxidized to NiIII, which reverted to NiII by urea reduction. When real human urine was used as the fuel, a power density of 4.46 mW/cm2 can be achieved at room temperature. This DUFC with high cell performance showed potential application in urea wastewater treatment.

Efficient photochemical denitrification by UV/sulfite system: Mechanism and applications.

Denitrification is an effective strategy to control eutrophication caused by excessive nitrate in water. However, the comparatively low efficiency of nitrate removal and N2 selectivity remains a challenge in the denitrification process. Herein, this study proposed a novel photochemical denitrification process by introducing hydrated electron (eaq-) to reduce nitrate in UV/sulfite system. The results indicated that the optimized UV/sulfite system could effectively reduce nitrate to N2 with a nearly 100% denitrification efficiency in 90 min. eaq- was identified as the mainly reactive species to achieve rapid removal of nitrate and nitrite, and the result was verified by quenching and laser flash photolysis tests. Benefiting from the high dispersion of eaq- in water and the rapid reaction rate between eaq- and the target, the generated N2O is susceptible to be reduced, leading to a high selectivity of N2 that was confirmed by 15N-isotopic. Besides, thermodynamic results based on the density functional theory (DFT) calculations suggested that the photochemical denitrification process was exothermic process and tend to transform to N2. Significantly, UV/sulfite system applied in the nickel-plating wastewater showed high denitrification efficiency, demonstrating that the novel photochemical denitrification process is promising for practical wastewater treatment.

Stereoselective preparation of P,axial-stereogenic allenyl bisphosphine oxides via chirality-transfer.

P,C-Stereogenic propargyl alcohols RC-3/SC-3' were prepared by the addition of (L)-menthyl-derived SPOs to propynals, which were converted to P,axial-stereogenic allenyl bisphosphine oxides. The chirality transfer was controlled by α-carbon via syn [2,3]-sigmatropic rearrangement. For SC-3' linking weak WDG on the alkynyl moiety, the chirality on the axis depended on stereogenic phosphorus.

Photoelectrocatalytic degradation of Ag-cyanide complexes and synchronous recovery of metallic Ag driven by TiO2 nanorods array photoanode combined with titanium cathode.

A photoelectrocatalytic (PEC) system for the decomposition of Ag-cyanide complexes synchronously with Ag recovery was established using the titanium dioxide nanorods (TiO2 NRs) as photoanode and the titanium plate as cathode. The removal efficiency of total cyanide was 76.58%, and the recovery ratio of Ag achieved 84.48% at the applied bias potential of 1.0 V vs SCE in the PEC process. During the reaction, the surface variations and photo-electric properties of TiO2 NRs photoanode or titanium cathode were characterized by SEM-EDS, XPS, and photoelectronic analyses. It was indicated that Ag2O and metallic Ag were deposited onto the TiO2 NRs photoanode and titanium cathode, respectively. Specifically, the in situ generated Ag2O on the TiO2 NRs photoanode facilitated the separation of the photogenerated charge carriers and enhanced the visible-light response, thus improving its PEC catalytic activity toward cyanide destruction. Combined with the results of active species quenching experiments, the mechanism of Ag-cyanide complexes decomposition and metallic Ag recovery by the PEC process was proposed.

Nucleophilic Substitution of P-Stereogenic Chlorophosphines: Mechanism, Stereochemistry, and Stereoselective Conversions of Diastereomeric Secondary Phosphine Oxides to Tertiary Phosphines.

A diastereomeric mixture of secondary phosphine oxide is stereospecifically converted to chlorophosphine salt by treatment with oxalyl chloride, which stereoselectively affords P-inverted or retained tertiary phosphines, depending on the substitution with aliphatic or aromatic Grignard reagents, respectively, in high to 99% yield and 99:1 dr. The repulsion of π-electron on aryl to lone electron pair on phosphorus is proposed for the P-retained substitution.

FBXW7 expression is associated with prognosis and chemotherapeutic outcome in Chinese patients with gastric adenocarcinoma.

BACKGROUND: FBXW7, a component of the Skp-Cullin1-F-box, mediates target protein recognition. It is a tumor suppressor gene that plays a role in the regulation of cell cycle exit and reentry via c-Myc, c-Jun and Notch degradation. There are few studies, particularly involving a large patient cohort, that have evaluated FBXW7 during gastric cancer progression. METHODS: Our study aimed to evaluate the value of FBXW7 as a clinical marker in gastric adenocarcinoma (GC) patients including a subset treated with postoperative chemotherapy. Quantitative reverse transcription PCR (qRT-PCR) assay was used to measure FBXW7 transcript levels in tumors paired with normal gastric tissue in 24 gastric adenocarcinoma patients. Subsequently, 546 additional GC samples were evaluated from patients that underwent radical gastrectomy, including 118 early stage cases(Stage I) and 428 advanced stage cases (Stages II or III). Amongst the advanced stage patient cases evaluated, 347 received postoperative adjuvant chemotherapy. All 546 gastric adenocarcinoma cases were then evaluated by tissue microarray and immunohistochemistry (IHC) for FBXW7 expression. Clinicopathological features and diagnoses were confirmed by histopathologic evaluation and review of clinical data. Overall survival (OS) was then evaluated in the 546 gastric cancer patients. RESULTS: By immunohistologic evaluation, low expression of FBXW7 in primary gastric cancer significantly correlated with poor differentiation of tumor cells. Moreover, low FBXW7 expression was associated with worse survival as well as worse adjuvant chemotherapy response. CONCLUSION: Our findings suggest that FBXW7 may serve as an important predictor in chemotherapeutic responses.

Enhanced Electroreductive Removal of Bromate by a Supported Pd-In Bimetallic Catalyst: Kinetics and Mechanism Investigation.

In this work, the electroreductive removal of bromate by a Pd1-In4/Al2O3 catalyst in a three-dimensional electrochemical reactor was investigated. A total of 96.4% of bromate could be efficiently reduced and completely converted into bromide within 30 min under optimized conditions. On the basis of the characterization results and kinetics analysis, a synergistic effect of Pd and In was observed, and Pd1-In4/Al2O3 had the highest reaction rate constant of 0.1275 min-1 (vs 0.0413, 0.0328, and 0.0253 min-1 for In/Al2O3, Pd/Al2O3, and Al2O3). The results of electron spin resonance and scavenger experiments confirmed that both direct electron transfer and indirect reduction by atomic H* were involved in the bromate removal process, while the direct reduction played a more important role. Moreover, the introduction of In could increase the zeta potential of Pd1-In4/Al2O3, facilitating bromate adsorption and its subsequent reduction on the catalyst. Finally, a reaction mechanism for bromate reduction by Pd1-In4/Al2O3 was proposed based on all the experimental results.

Dechlorination of Trichloroacetic Acid Using a Noble Metal-Free Graphene-Cu Foam Electrode via Direct Cathodic Reduction and Atomic H.

A three-dimensional graphene-copper (3D GR-Cu) foam electrode prepared by chemical vapor deposition method exhibited superior electrocatalytic activity toward the dechlorination of trichloroacetic acid (TCAA) as compared to the Cu foam electrode. The cyclic voltammetry and electrochemical impedance spectra analysis confirmed that GR accelerated the electron transfer from the cathode surface to TCAA. With the applied cathode potential of -1.2 V (vs SCE), 95.3% of TCAA (500 µg/L) was removed within 20 min at pH 6.8. TCAA dechlorination at the Cu foam electrode was enhanced at acidic pH, while a slight pH effect was observed at the GR-Cu foam electrode with a significant inhibition for Cu leaching. The electrocatalytic dechlorination of TCAA was accomplished via a combined stepwise and concerted pathway on both electrodes, whereas the concerted pathway was efficiently promoted on the GR-Cu foam electrode. The direct reduction by electrons was responsible for TCAA dechlorination at Cu foam electrode, while at GR-Cu foam electrode, the surface-adsorbed atomic H* also contributed to TCAA dechlorination owing to the chemical storage of hydrogen in the GR structure. Finally, the potential applicability of GR-Cu foam was revealed by its stability in the electrocatalytic dechlorination over 25 cycles.

Sarcomatoid carcinoma of the stomach: A case report and literature review.

Sarcomatoid carcinoma of the stomach is a rare type of malignant tumor, characterized by distinct cellular morphology. This type of tumor is even more rare in giant size. The present study reports a case of giant sarcomatoid carcinoma, which developed in the distal stomach. A 49-year-old male underwent medical investigation for gastrointestinal hemorrhage. Endoscopic examination, computed tomography (CT) and positron emission tomography-CT scan identified a giant neoplasm, which involved the gastric antrum and body, gallbladder and hepatic flexure of the colon. Surgery was performed to excise the tumor, which was ~14×13×8 cm in size. A diagnosis of sarcomatoid carcinoma was made since the tumor was positive for epithelial markers, even within the mesenchymal elements. To the best of our knowledge, only 5 cases of sarcomatoid carcinoma of the stomach have been previously reported, and a tumor that has been able to be resected despite such a large size has never been reported.

Graphene-modified Pd/C cathode and Pd/GAC particles for enhanced electrocatalytic removal of bromate in a continuous three-dimensional electrochemical reactor.

Bromate (BrO3(-)) is a carcinogenic and genotoxic contaminant commonly generated during ozonation of bromide-containing water. In this work, the reductive removal of BrO3(-) in a continuous three-dimensional electrochemical reactor with palladium-reduced graphene oxide modified carbon paper (Pd-rGO/C) cathode and Pd-rGO modified granular activated carbon (Pd-rGO/GAC) particles was investigated. The results indicated that the rGO sheets significantly promoted the electrochemical reduction of BrO3(-). With the enhanced electron transfer by rGO sheets, the electroreduction of H2O to atomic H* on the polarized Pd particles could be significantly accelerated, leading to a faster reaction rate of BrO3(-) with atomic H*. The synergistic effect of the Pd-rGO/C cathode and Pd-rGO/GAC particles were also exhibited. The atomic H* involved in various electroreduction processes was detected by electron spin resonance spectroscopy and its role for BrO3(-) reduction was determined. The performance of the reactor was evaluated in terms of the removal of BrO3(-) and the yield of Br(-) as a function of the GO concentration, Pd loading amount, current density, hydraulic residence time (HRT), and initial BrO3(-) concentration. Under the current density of 0.9 mA/cm(2), BrO3(-) with the initial concentration of 20 µg/L was reduced to be less than 6.6 µg/L at the HRT of 20 min. The BrO3(-) reduction was inhibited in the presence of dissolved organic matter. Although the precipitates generated from Ca(2+) and Mg(2+) in the tap water would cover the Pd catalysts, a long-lasting electrocatalytic activity could be maintained for the 30 d treatment. SEM and XPS analysis demonstrated that the precipitates were predominantly deposited onto the Pd-rGO/C cathode rather than the Pd-rGO/GAC particles.

Characterization of dissolved organic matter from surface waters with low to high dissolved organic carbon and the related disinfection byproduct formation potential.

In this study, the disinfection byproduct formation potential (DBPFP) of three surface waters with the dissolved organic carbon (DOC) content of 2.5, 5.2, and 7.9mg/L was investigated. The formation and distribution of trihalomethanes and haloacetic acids were evaluated. Samples collected from three surface waters in China were fractionated based on molecular weight and hydrophobicity. The raw water containing more hydrophobic (Ho) fraction exhibited higher formation potentials of haloacetic acid and trihalomethane. The DBPFP of the surface waters did not correlate with the DOC value. The values of DBPFP per DOC were correlated with the specific ultraviolet absorbance (SUVA) for Ho and Hi fractions. The obtained results suggested that SUVA cannot reveal the ability of reactive sites to form disinfection byproducts for waters with few aromatic structures. Combined with the analysis of FTIR and nuclear magnetic resonance spectra of the raw waters and the corresponding fractions, it was concluded that the Ho fraction with phenolic hydroxyl and conjugated double bonds was responsible for the production of trichloromethanes and trichloroacetic acids. The Hi fraction with amino and carboxyl groups had the potential to form dichloroacetic acids and chlorinated trihalomethanes.

Electrochemical removal of haloacetic acids in a three-dimensional electrochemical reactor with Pd-GAC particles as fixed filler and Pd-modified carbon paper as cathode.

The reductive removal of haloacetic acids (HAAs) in a three-dimensional electrochemical continuous reactor with Pd-granular activated carbon (Pd-GAC) particles as fixed filler and Pd-modified carbon paper (Pd-C) as cathode was studied in this research. Pd-C electrode was prepared from PdCl2 via electrodeposition onto carbon paper. Pd-GAC particles were prepared by the impregnation of Pd(2+) ions onto GAC. Efficient electrocatalytic reduction of HAAs in this reactor was exhibited. Effects of current density, initial HHAs concentration, and hydraulic retention time on the HHAs removal were investigated. Under the current density of 0.3 mA/cm(2), HAAs with initial concentration of 120 µg/L were reduced to be less than 60 µg/L with hydraulic retention time of 20 min. Electron transfer and HAAs diffusion both played an important role in controlling the electro-reduction process under the conditions of current density less than 0.6 mA/cm(2) with an initial HAAs concentration ranging from 120 to 600 µg/L. However, the HAAs diffusion became the primary rate-limiting step when the current density was higher than 0.6 mA/cm(2). The Pd(0) and Pd(2+) species were detected by X-ray photoelectron spectroscopy. The stability of the electrochemical reactor in the reduction removal of HAAs was also exhibited.

Efficient treatment of an electroplating wastewater containing heavy metal ions, cyanide, and organics by H2O2 oxidation followed by the anodic Fenton process.

A real electroplating wastewater, containing heavy metals, cyanide, and organic contaminants, was treated by electrocoagulation (EC), H2O2 oxidation, H2O2 pre-oxidation followed by EC, and the anodic Fenton process and the efficacy of the processes was compared. Concentration of cyanide, Cu, Ni, Zn, and Cr was largely decreased by EC within 5 min. When the reaction time was extended, removal of residual cyanide, Cu, and Ni was limited. In H2O2 oxidation, the concentration of cyanide decreased from initial 75 to 12 mg L(-1) in 30 min. The effluents from the H2O2 oxidation were further treated by EC or anodic Fenton. In EC, the concentration of total cyanide, Ni, and Cu decreased to below 0.3, 0.5, and 1.5 mg L(-1), respectively. Removal efficiency of chemical oxygen demand by EC was less than 20.0%. By contrast, there was 73.5% reduction by the anodic Fenton process with 5 mM H2O2 at 30 min; this can be attributed to the oxidation induced by hydroxyl radicals generated by the reaction of H2O2 with the electrogenerated Fe(2+). Meanwhile, residual cyanide, Cu, and Ni can also be efficiently removed. Transformation of organic components in various processes was analyzed using UV-visible and fluorescence excitation-emission spectra.