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Differential removal of tetracycline hydrochloride and quinolone antibiotics by calcined and uncalcined layered double hydroxides
No full textAntibiotics generally cause drug-resistant genes (ARGs) and drug-resistant bacteria (ARBs). With a complex class of antibiotics, it is very crucial to select specific adsorbents for different kinds of antibiotics. Zn-Al layered double hydroxide (LDH) and calcined layered double hydroxide (LDO) were prepared as absorbents for tetracycline hydrochloride (TCH) and ofloxacin (OFX), which were two antibiotics with different structures. According to the results of the adsorption experiments, LDO has the best adsorption capacity on TCH, reaching 322.58 mg/g. Acid-base titration, XRD, TEM, SEM, BET, and FI-TR analyses indicate that LDO has more active sites on the surface, the “memory effect”, and a larger specific surface area. In contrast, the removal rate of OFX by LDO is low because OFX has a more stable quinolone ring structure. Furthermore, after five adsorption-desorption cycles, the adsorption rate of TCH remains at 94.9%, demonstrating that LDO has good cyclic adsorption capacity for TCH. This study creatively combines acid-base buffering characteristics to study the mechanism of the adsorption of antibiotics by hydrotalcite, and proposes that LDO can be used as a special adsorbent for TCH
Pre-operative electrodiagnostic studies and intraoperative neurophysiologic monitoring: power and pitfalls
No full textOutpatient electrodiagnostic studies and intraoperative monitoring are essential tools for the surgical management of nerve injury. Decisions are based on the diagnostic certainty afforded by outpatient electrodiagnostic studies, which are more sensitive and specific than clinical examinations regarding the nature and localization of a nerve lesion. Intraoperative neurophysiologic monitoring detects changes in neurologic function during surgery. It provides significantly better information than visual inspection of the operative field, minimizing postoperative neurologic deficits due to surgical manipulation (e.g., stretching, compression, heating from electrocauterization, constriction, or clamping of local blood vessels). These techniques exploit similar neurophysiologic principles to afford enhanced diagnostic and real-time functional data during surgery. However, an understanding of their limitations is critical for the interpretation of these data. This review discusses these techniques, including their use, advantages, and disadvantages in diagnosing and managing three essential nerve lesions amenable to surgical management-radiculopathy, mononeuropathy, and brachial plexopathy
Lysine-modulated synthesis of enzyme-embedded hydrogen-bonded organic frameworks for efficient carbon dioxide fixation
No full textCarbonic anhydrase (CA) is an important carbon fixation enzyme. Immobilization of CA can expand its application in the realm of adsorption, catalysis, and so on. As a typical metal-free framework, hydrogen-bonded organic frameworks (HOFs) featuring mild synthesis process, exquisite framework structure and good enzyme compatibility have been used for enzyme embedding. However, the catalytic performance of CA-embedded HOFs (CA@HOFs) is limited by the micropore size of HOFs and the slow adsorption of CO2. Herein, CA@Lys-HOF-1 was synthesized by introducing lysine (Lys), a basic amino acid, during the coprecipitation of CA and HOFs for CO2 fixation. The addition of Lys enlarged the average pore size of HOF-1 from 1.8 to 3.2 nm, whereas the introduced -NH2 groups increased the initial adsorption of CO2 from 0.55 to 1.21 cm3 g-1. Compared to CA@HOF-1, the activity of CA@Lys-HOF-1 was enhanced by 71.25%, and the corresponding production of CaCO3 was enhanced by 12.7%. After eight reaction cycles, CA@Lys-HOF-1 still maintained an output of 9.97 mg of CaCO3 every 5 min, 83.7% of the initial production. It is hoped that the CA@Lys-HOF-1 reported offers a platform for efficient and continuous fixation of CO2
Quantitative detection of organic mercury in whole blood using derivatization and gas chromatography-negative chemical ionization-mass spectrometry
No full textThe Minamata disease, first identified in Japan in the 1950s, is caused by severe methylmercury (MeHg) poisoning. To prevent the development of this disease, routine evaluation of MeHg levels in blood samples is crucial. The purpose of this research was to explore the use of derivatization and capillary gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) for the quantitative detection of both organic and inorganic mercury in blood samples. Alkyl mercury in standard solutions was extracted as halide salts in toluene with hydrohalic acid. Fat contents in whole blood samples were removed by methyl isobutyl ketone and hexane using a cysteine/alkaline solution and then organic mercury was extracted as a bromide complex using toluene and cupper chloride solution. The linearity of the response ratio vs. concentration curves (R2) was 0.987 for methylmercury bromide and 0.990 for ethylmercury (EtHg) bromide, over the calibration range of 0.02 ng/mL to 20 ng/mL. The recovery of MeHg and EtHg was 67.1% and 49.3%, respectively. The concentrations of MeHg in whole blood samples determined using GC with an electron capture detector agreed with those determined using GC-NCI-MS, with a correlation coefficient of 0.923. The mean concentration of MeHg in a certified reference material (NMIJ CRM 7402-a) determined using GC-NCI-MS was 0.64 μg/g, comparable with the certified value of 0.58 μg/g. Our study demonstrates a simple and low-cost approach for analyzing mercury in biological samples, although further optimization is required given the relatively low recovery and the concern about the toxicity of methyl isobutyl ketone
Management of soft tissue defects of the thumb
No full textHand surgery has undergone substantial changes in recent years, especially for reconstructive surgery techniques. We discuss the management of soft tissue defects of the thumb, discussing indications, and operative pearls and pitfalls. We cover non-operative treatment and local advancement flaps for small distal soft tissue defects and pedicled flaps for more significant defects. We also discuss composite vascularized free flaps such as second-toe neurocutaneous flaps and partial hallux transfer for compound defects or total amputations. This article aims to provide hand surgeons with an update on reconstructing an injured thumb
The effect of chromium content on the corrosion behavior of ultrafine-grained CrxMnFeCoNi high-entropy alloys in sulfuric acid solution
No full textChromium (Cr) plays a critical role in the corrosion resistance of conventional alloys via the formation of a dense Cr oxide-based passive film. However, the exact role of Cr in the corrosion of high-entropy alloys (HEAs) remains unclear. The effect of Cr content on the corrosion behavior of the ultrafine-grained CrxMnFeCoNi (x = 0, 0.6, 1, and 1.5) HEAs in the sulfuric acid solution (0.5 M H2SO4) was investigated. These HEAs were fabricated using a combination of mechanical alloying and spark plasma sintering. The electrochemical tests show that the passive film was more compact and thicker at higher Cr concentration, but the corrosion rate first increased and then decreased, due to the presence of the nanocrystalline-amorphous phase boundaries in the passive film. Long-time immersion tests show that the corrosion rate increased exponentially with the Cr content, due to the gradual accumulation of the galvanic corrosion
Circular economy without chemicals controls? Evidence of recirculated toxic plasticizers in flexible PVC products
No full textThe global push towards a circular economy (CE) has led to increasing efforts to improve resource utilization efficiency, including plastics recycling. However, the presence of additives, especially those that are toxic, complicates plastics recycling in several ways. Without sufficient controls, the spread of hazardous additives via recycling activities represents a significant public health challenge, particularly among developing nations. This study demonstrates evidence of such uncontrolled recycling, based on an investigation of four household flexible PVC product groups available in Thailand. A versatile pyrolysis/thermal desorption gas chromatography-mass spectrometry (Py/TD-GC-MS) method was employed to simultaneously screen 18 target plasticizers in these products. Di-(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP) are the most frequently detected primary plasticizers. DEHP is dominant in vinyl boots, flooring sheets, and hoses, while DINP is dominant in cable sheaths, likely due to a spill-over effect from the EU Restriction of Hazardous Substances (RoHS) directive. Chlorinated paraffins (CPs) are secondary plasticizers that are also detected in most samples, except for boots. The other plasticizers detected include other ortho-phthalates and non-phthalates. These results provide insight into combinatory patterns of plasticizer ‘cocktails’, that comprise restricted, as-yet-unrestricted, and non-restricted plasticizers, embedded in the same individual samples, with a maximum of seven plasticizers found in a single cable sheath. These findings indicate the existence of potentially risky recycling practices that target embedded plasticizers to save cost, without due consideration of their inherent toxicity. Proper interventions are necessary to ensure that CE and chemical safety can be synergized
Assessment of response to liver directed radiation-based therapies: Current guidelines, challenges, and future directions
No full textRadiation-based local-regional therapies for hepatocellular carcinoma (HCC) have gained wide acceptance due to promising rates of tumor response, survival, and safety profiles. After treatment, it is important to assess tumor response to determine further management, patient prognosis, and endpoint outcomes for clinical trials. To standardize imaging interpretation and reporting of HCC response to local-regional treatment, a few imaging-based response assessment systems were developed. Two of them have emerged as the most used: the Liver Imaging Reporting and Data System (LI-RADS) Treatment Response Algorithm (LR-TRA) and the modified Response Evaluation Criteria in Solid Tumors (mRECIST). While these systems have been validated for the assessment of response to ablative locoregional therapies, assessment of response to radiation-based therapies can be challenged by persistent or evolving imaging features and is still an area of active research. Following the advances in technology and a better understanding of tumor biology that allowed for the increased application of radiation-based local-regional therapies for the treatment of HCC, research is still needed to address the limitations of current imaging criteria for assessing tumor response to these novel techniques. In this review, we describe radiation-based liver-directed treatment options, examine imaging criteria for assessing treatment response, discuss practical limitations and gaps in knowledge when applying these response criteria, and address future directions that may help to improve accuracy and outcomes when assessing response to radiation-based HCC treatment
Accelerating redox kinetics by ZIF-67 derived amorphous cobalt phosphide electrocatalyst for high-performance lithium-sulfur batteries
No full textThe feasibility of the commercialization of lithium-sulfur (Li-S) batteries is troubled by sluggish redox conversion kinetics and the shuttle effect of polysulfides. Herein, a zeolitic imidazolate framework derived amorphous CoP combined with carbon nanotubes conductive network composites (aCoP@CNTs) has been synthesized as an effective dual-electrocatalyst for accelerating the redox kinetics of polysulfides to prolong the lifespan of Li-S batteries. Compared with crystalline CoP, unsaturated Co atoms of aCoP@CNTs exhibit stronger chemical adsorption capacity for polysulfides and serve as catalytic centers to accelerate the conversion from soluble polysulfides to solid-state lithium sulfide. Meanwhile, the 3D porous conductive network not only facilitates ion/electron transportation but also forms a physical barrier to limit the migration of polysulfides. Benefiting from the above preponderances, the batteries with aCoP@CNTs modified interlayer exhibited excellent cycle stability (initial discharge capacity of 1227.9 mAh g-1 at 0.2 C), rate performance (795.9 mAh g-1 at 2.5 C), long-term cycle reliability (decay rate of 0.049% per cycle at 1 C over 1000 cycles), and superior high-loading performance (high initial discharge capacity of 886 mAh g-1 and 753.6 mAh g-1 at 1 C under high S loading of 3 mg cm-2 and 4 mg cm-2)
LCA-based environmental sustainability assessment of hybrid additive manufacturing of a turbine blade
No full textIn this paper, a cradle-to-gate life cycle assessment (LCA) method is used to compare the overall energy consumption and environmental impact of hybrid additive manufacturing (HAM) and the traditional CNC milling process with a case study of turbine blade manufacturing. Six environmental impacts are assessed in this study: acidification potential (AP), eutrophication potential (EP), global warming potential (GWP), photochemical ozone creation potential (POCP), ozone depletion potential (ODP), and abiotic depletion potential (ADP). The results suggest that HAM can not only reduce energy consumption and material waste but also reduce the environmental impact by 53% from a life cycle perspective. Specifically, the results of GWP, AP, EP, ODP, POCP and ADP of the HAM are only 32.2%, 34.6 %, 44.7%, 27.2%, 25.6%, and 24.7 % of that in traditional CNC machining
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