High-carbon-content biochar from chemical manufacturing plant sludge for effective removal of ciprofloxacin from aqueous media.

Biochar is considered a promising biosorbent for harmful organic pollutants in aqueous media. However, only a limited number of biochars derived from industrial sludges have been utilized due to their problematic high ash content and heavy metal leaching. In this study, a highly effective biochar was prepared as a superabsorbent for ciprofloxacin (CIP) from chemical manufacturing plant sludge via K2CO3-activated pyrolysis, and its CIP removal behavior was evaluated. Unlike sewage sludge, chemical manufacturing plant sludge contains low SiO2, resulting in an ultra-pure carbon (95.4%) based biochar with almost negligible ash content. As the pyrolysis temperature increased from 400 to 800 °C, the ordered graphitic carbon structure transformed into an amorphous carbon phase, and most oxygen-containing groups disappeared. However, the pore size significantly decreased to ∼4.5 nm due to the corrosive carbon volatilization caused by K2CO3, resulting in an extremely large surface area of 2331.8 m2/g. Based on its large surface area and porous carbon structure, the activated biochar at 800 °C (CAB-800) exhibited an outstanding CIP adsorption capacity of 555.56 mg/g. The CIP adsorption isotherm, kinetic, and thermodynamic studies were systematically investigated. The CIP adsorption on CAB-800 was mainly attributed to π-π interactions and hydrogen bond formation, with electrostatic interactions partially contributing to the adsorption reaction. From pH 2 to 12, CAB-800 showed an excellent CIP adsorption capacity of over 316.7 mg/g, with adsorption favored under acidic conditions. Except for HCO3- and CO32-, the presence of anions and humic acids did not significantly affect CIP adsorption capacity. These results demonstrate that biochar produced from chemical manufacturing industry sludge via K2CO3 activation is a highly feasible material for the removal of CIP from aqueous media.

Topological Fermi-arc surface state covered by floating electrons on a two-dimensional electride.

Two-dimensional electrides can acquire topologically non-trivial phases due to intriguing interplay between the cationic atomic layers and anionic electron layers. However, experimental evidence of topological surface states has yet to be verified. Here, via angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM), we probe the magnetic Weyl states of the ferromagnetic electride [Gd2C]2+·2e-. In particular, the presence of Weyl cones and Fermi-arc states is demonstrated through photon energy-dependent ARPES measurements, agreeing with theoretical band structure calculations. Notably, the STM measurements reveal that the Fermi-arc states exist underneath a floating quantum electron liquid on the top Gd layer, forming double-stacked surface states in a heterostructure. Our work thus not only unveils the non-trivial topology of the [Gd2C]2+·2e- electride but also realizes a surface heterostructure that can host phenomena distinct from the bulk.

Powdered activated carbon (PAC)-assisted peroxymonosulfate activation for efficient urea elimination in ultrapure water production from reclaimed water.

Urea is a problematic pollutant in reclaimed water for ultrapure water (UPW) production. The sulfate radical-based advanced oxidation process (SR-AOP) has been recognized as an effective method for urea degradation. However, conventional metal-based catalysts for peroxymonosulfate (PMS) activation are unsuitable for UPW production due to issues related to metal ion leaching. In this study, the use of powdered activated carbon (PAC) was investigated for the removal of urea from reclaimed water. The PAC exhibited a high degree of defects (ID/IG = 1.709) and various surface oxygen functional groups (C-OH, C=O, and C-O), which greatly enhanced its catalytic capability. The PAC significantly facilitated PMS activation in the PMS + PAC system, leading to the complete urea decomposition. The PMS + PAC system demonstrated excellent urea removal efficiency within a wide pH range, except for pH < 3. Among the various anions present, the CO32- and PO43- inhibited urea degradation, while the coexistence of Cl- promoted urea removal. Furthermore, the feasibility test was evaluated using actual reclaimed water. The quenching test revealed that SO4-·, ·OH, and O2-· played crucial roles in the degradation of urea in the PAC-assisted SR-AOP. The oxygen functional groups (C-OH and O-C=O) and defect sites of PAC clearly contributed to PMS activation.

Converting the Bulk Transition Metal Dichalcogenides Crystal into Stacked Monolayers via Ethylenediamine Intercalation.

We report the synthesis of ethylenediamine-intercalated NbSe2 and Li-ethylenediamine-intercalated MoSe2 single crystals with increased interlayer distances and their electronic structures measured by means of angle-resolved photoemission spectroscopy (ARPES). X-ray diffraction patterns and transmission electron microscopy images confirm the successful intercalation and an increase in the interlayer distance. ARPES measurement reveals that intercalated NbSe2 shows an electronic structure almost identical to that of monolayer NbSe2. Intercalated MoSe2 also returns the characteristic feature of the monolayer electronic structure, a direct band gap, which generates sizable photoluminescence even in the bulk form. Our results demonstrate that the properties and phenomena of the monolayer transition metal dichalcogenides can be achieved with large-scale bulk samples by blocking the interlayer interaction through intercalation.

Case Report of a Post-Traumatic Hydrocephalus Patient: Ventriculo-Vesicle Shunt With a Review of the Literature.

Post-traumatic hydrocephalus (PTH) is treated through cerebrospinal fluid (CSF) diversion, typically through ventriculoperitoneal shunt (VPS) or other bypass techniques. As these shunts are associated with significant complications and high revision rates in certain populations, it is important to tailor a patient's shunt procedure according to their medical history and complications. Herein, we report the case of a 30-year-old man with PTH following a traffic accident on a motorcycle. VPS was chosen as the method of treatment but required multiple revisions and replacements due to persistent complications such as post-operative infection, shunt obstruction and abdominal problem. As the patient's heart failure and pleural effusion rendered both ventriculopleural and ventriculoatrial shunt not feasible, it was decided to move the shunt to the bladder (ventriculo-vesicle shunt [VVS]) in cooperation with a urologist. Follow-up examinations after about 3 months showed a decrease in ventricle size, improved hydrocephalus, and no complications such as urinary infection or bladder stone formation. In cases where the patient's underlying conditions, such as heart failure and pleural effusion, make it unsuitable to choose the pleural cavity or atrium as non-peritoneal spaces, VVS can be a suitable option for continuous CSF drainage when complications have occurred with the previous VPS.

Factors Associated With Short-Term Outcomes of Burr-Hole Craniostomy Associated With Brain Re-Expansion and Subdural Hematoma Shrinkage for Chronic Subdural Hematoma.

Objective: Chronic subdural hematoma (CSDH) is a commonly encountered neurosurgical pathology that frequently requires surgical intervention. With an increasingly aging demographic, more older people and patients with comorbidities will present with symptomatic CSDH. This study evaluated clinical and laboratory factors affecting the short-term outcomes of CSDH after surgical intervention. Methods: We retrospectively analyzed 170 patients who underwent burr-hole trephination for CSDH in a single institution from January 2019 to December 2021. All patients were examined for risk factors and evaluated for hematoma thickness change and midline shifting on brain computed tomography (CT) scans at 3 days after burr-hole trephination. Results: This consecutive series of patients included 114 males (67.1%) and 56 females (32.9%); mean age 72.4±12.5 years. Renal disease (p=0.044) and prior intracranial hemorrhage (p=0.004) were clinical factors associated with poorer prognosis. A statistically significant association was found between initial laboratory findings, including high creatine kinase (p=0.025) and low platelet (p=0.036) levels, and CT findings 3 days postoperatively. The 3-day mean arterial pressure and postoperative ambulation were not significantly associated with outcomes. Conclusion: Burr-hole craniostomy is an effective surgical procedure for initial CSDH. However, patients with a history intracranial hemorrhage and abnormal laboratory findings, such as low platelet levels, who underwent burr-hole trephination had poor short-term outcomes. Therefore, these patients should be carefully monitored.

Quantum electron liquid and its possible phase transition.

Purely quantum electron systems exhibit intriguing correlated electronic phases by virtue of quantum fluctuations in addition to electron-electron interactions. To realize such quantum electron systems, a key ingredient is dense electrons decoupled from other degrees of freedom. Here, we report the discovery of a pure quantum electron liquid that spreads up to ~3 Å in a vacuum on the surface of an electride crystal. Its extremely high electron density and weak hybridization with buried atomic orbitals show the quantum and pure nature of the electrons, which exhibit a polarized liquid phase, as demonstrated by our spin-dependent measurement. Furthermore, upon enhancing the electron correlation strength, the dynamics of the quantum electrons change to that of a non-Fermi liquid along with an anomalous band deformation, suggestive of a transition to a hexatic liquid crystal phase. Our findings develop the frontier of quantum electron systems and serve as a platform for exploring correlated electronic phases in a pure fashion.