Defective zirconium/titanium bimetallic metal-organic framework as a highly selective and sensitive electrochemical aptasensor for deoxynivalenol determination in foodstuffs.

An electrochemical aptsensor for deoxynivalenol determination was successfully designed and constructed based on a defective bimetallic organic framework (denoted as ZrTi-MOF). The high porosity, large specific surface area, several structural defects, mixed metal clusters, and rich functionality of ZrTi-MOF markedly enhanced its electrochemical activity and facilitated the aptamer immobilization. As a result, the ZrTi-MOF-based aptasensor shows high sensitivity to detect deoxynivalenol via specific recognition between aptamer and deoxynivalenol, as well as the formation of aptamer-deoxynivalenol complex. On this basis, the developed ZrTi-MOF-based impedimetric aptasensor showed a low detection limit of 0.24 fg mL-1 for deoxynivalenol determination in the deoxynivalenol concentration range 1 fg mL-1- 1 ng mL-1 under optimized conditions, which also exhibited satisfactory selectivity, stability, reproducibility, and regenerability. Furthermore, determination of deoxynivalenol was achieved in bread and wheat flour samples via the developed ZrTi-MOF-based deoxynivalenol aptasensor. The result from this study showed that the ZrTi-MOF-based electrochemical aptasensor could become a promising strategy for detecting deoxynivalenol in foodstuffs in the future.

Development of oxidized hydroxyethyl cellulose-based hydrogel enabling unique mechanical, transparent and photochromic properties for contact lenses.

With the development of smart devices, higher requirements are put forward for the stimuli-responsive materials. Stimuli-hydrogels as one kind of stimuli-responsive materials with hydrophilicity, demonstrate huge potential in developing intelligent devices for biomedical application. On this basis, we herein report that a sample method was devised to develop a novel composite hydrogel mainly based on oxidized hydroxyethyl cellulose and allyl co-polymer. Subsequently, a series of tests toward this oxidized hydroxyethyl cellulose-based hydrogel due to its structure and performance was applied. Here, the oxidized hydroxyethyl cellulose molecular chains were used as biomacromolecule templates to form Schiff base, borate and hydrogen bonds to obtain unique mechanical properties (fast recovery with almost no-hysteresis and remarkable compressive capacity), while a double bond functionalized spirooxazine (allyl spirooxazine derivative) was applied to endow photo- and pH sensitivity to the oxidized hydroxyethyl cellulose-based transparent hydrogel (T% = 93%) substrate. Furthermore, the oxidized hydroxyethyl cellulose-based hydrogel did exhibit good pH environment adaptability and noncytotoxicity in vitro test. Based on the advanced characteristics, the designed oxidized hydroxyethyl cellulose-based hydrogel has potential applications prospect in the development of safe, fashionable and pH- detectable contact lenses, thereby providing a new strategy for the development of smart, stylish contact lenses.

Nanodiamonds and hydrogen-substituted graphdiyne heteronanostructure for the sensitive impedimetric aptasensing of myocardial infarction and cardiac troponin I.

A novel heteronanostructure of nanodiamonds (NDs) and hydrogen-substituted graphdiyne (HsGDY) (denoted as HsGDY@NDs) was prepared for the impedimetric aptasensing of biomarkers such as myoglobin (Myo) and cardiac troponin I (cTnI). Basic characterizations revealed that the HsGDY@NDs were composed of nanospheres with sizes of 200-500 nm. In these nanospheres, NDs were embedded within the HsGDY network. The HsGDY@NDs nanostructure, which integrated the good chemical stability and three-dimensional porous networks of HsGDY, and the good biocompatibility and electrochemical activity of NDs, could immobilize diverse aptamer strands and recognize target biomarkers. Compared with HsGDY- and NDs-based aptasensors, the HsGDY@NDs-based aptasensors exhibited superior sensing performances for Myo and cTnI, giving low detection limits of 6.29 and 9.04 fg mL-1 for cTnI and Myo, respectively. In addition, the HsGDY@NDs-based aptasensors exhibited high selectivity, good stability, reproducibility, and acceptable applicability in real human serum. Thus, the construction of HsGDY@NDs-based aptasensor is expected to broaden the application of porous organic frameworks in the sensing field and provide a prospective approach for the early detection of disease biomarkers.

Multifunctional metal-organic frameworks in oil spills and associated organic pollutant remediation.

The release of toxic organic compounds into the environment in an event of oil spillage is a global menace due to the potential impacts on the ecosystem. Several approaches have been employed for oil spills clean-up, with adsorption technique proven to be more promising for the total reclamation of a polluted site. Of the several adsorbents so far reported, adsorbent-based porous materials have gained attention for the reduction/total removal of different compounds in environmental remediation applications. The superior potential of mesoporous materials based on metal-organic frameworks (MOFs) against conventional adsorbents is due to their intriguing and enhanced properties. Therefore, this review presents recent development in MOF composites; methods of preparation; and their practical applications towards remediating oil spill, organic pollutants, and toxic gases in different environmental media, as well as potential materials in the possible deployment in reclaiming the polluted Niger Delta due to unabated oil spillage and gas flaring.

The Comparison of HHHFNC and NCPAP in Extremely Low-Birth-Weight Preterm Infants After Extubation: A Single-Center Randomized Controlled Trial.

Objectives: To compare the clinical efficacy of heated, humidified high-flow nasal cannula (HHHFNC) and nasal continuous positive airway pressure (NCPAP) in extremely low-birth-weight preterm infants (ELBWI) after extubation. Methods: This trial included 94 extremely low-birth-weight infants (ELBWI), within 7 days after birth, and prepared for tracheal extubation and a change to non-invasive ventilation in the neonatal intensive care unit (NICU) admitted to our hospital from January 2015 to December 2018, with 48 infants in the HHHFNC group and 46 infants in the NCPAP group. Reintubation rate within 72 h after initial extubation, total ventilation time, non-invasive ventilation time, total oxygen inhalation time, and the time to reach full enteral feeding were the primary outcome measures. Total intestinal feeding time, average weight gain rate, days of hospitalization, costs of hospitalization, and complication rates, including nasal injury, IVH, BPD, NEC, ROP, and PDA, were used as secondary outcomes. Data were analyzed using Student's t-test or the Mann-Whitney U-test with a Chi-square test or Fisher's exact test, as appropriate, in SPSS (25.0). Results: HHHFNC not only shortened the oxygen exposure time but also effectively reduced the incidence of nasal injury (6.25 vs. 36.96%) and NEC (10.42 vs. 28.26%) (P < 0.05). Additionally, HHHFNC achieved a significant advance in the time to reach full enteral feeding (31.24 ± 11.35 vs. 34.21 ± 14.09 days); increased the average weight gain rate (16.07 ± 3.10 vs. 13.74 ± 4.21) and reduced the days of hospitalization (73.45 ± 18.84 vs. 79.24 ± 19.75), with a lower cost of hospitalization (16.04 ± 3.64 vs.18.79 ± 4.13) thousand dollars (all P < 0.05). Conclusions: Compared with NCPAP, HHHFNC was effective in preventing extubation failure in mechanically ventilated preterm ELBWI. HHHFNC shortens oxygen consumption time and significantly reduces the incidence of nasal injury and necrotizing enterocolitis; moreover, it can also reduce the length of stay and the hospitalization costs.

Insights into the Surface Oxygen Functional Group-Driven Fast and Stable Sodium Adsorption on Carbon.

Engineering the oxygen functional groups (OFGs) is a dynamic strategy to tune the surface chemistry and electrochemical properties of carbon-based materials. In this paper, the species and contents of OFGs on the surface of ordered mesoporous carbon (OMC) and their effects on the sodium storage performance are systematically investigated without the interference of interlayer distance variation, extrinsic defects, other heteroatoms (e.g., N, S), etc. Theoretical calculations performed on various OFGs demonstrate that quinones and carboxylic anhydride groups possess two C═O bonds with stable configurations, good electronic conductivity, and strong sodium adsorption capability, contributing greatly to the Na+ storage capacity compared to the carboxylic acid groups. The ex situ techniques disclose the evolution of the OFGs and manifest the stable coordination of Na+ with C═O bonds even after long cycles. The optimized OFGs boost the Na+ redox reaction kinetics and enhance the surface capacitance contribution, achieving a capacity enhancement of 64.7% compared to the pristine OMC. This work would present implications in rational designing of oxygen-functionalized carbon materials for energy storage fields.

Defect formation-induced tunable evolution of oxygen functional groups for sodium storage in porous graphene.

The coinciding effects of carbon defects and oxygen functional groups in porous graphene were demonstrated in this work. The species and distributions of oxygen functional groups evolved with the types of defects, especially those containing C[double bond, length as m-dash]O bonds mainly distributed along the edge of ring defects, and enhanced Na+ storage.

Autologous cord blood cell infusion in preterm neonates safely reduces respiratory support duration and potentially preterm complications.

Preterm birth and its complications are the leading cause of neonatal death. The main underlying pathological mechanisms for preterm complications are disruption of the normal maturation processes within the target tissues, interrupted by premature birth. Cord blood, as a new and convenient source of stem cells, may provide new, promising options for preventing preterm complications. This prospective, nonrandomized placebo controlled study aimed at investigating the effect of autologous cord blood mononuclear cells (ACBMNC) for preventing preterm associated complications. Preterm infants less than 35 weeks gestational age were assigned to receive ACBMNC (5 × 107 cells/kg) intravenous or normal saline within 8 hours after birth. Preterm complication rates were compared between two groups to demonstrate the effect of ACBMNC infusion in reducing preterm complications. Fifteen preterm infants received ACBMNC infusion, and 16 infants were assigned to the control group. There were no significant differences when comparing mortality and preterm complication rates before discharge. However, ACBMNC infusion demonstrated significant decreases in duration of mechanical ventilation (3.2 days vs 6.41 days, P = .028) and oxygen therapy (5.33 days vs 11.31 days, P = .047). ACBMNC infusion was effective in reducing respiratory support duration in very preterm infants. Due to the limited number of patients enrolled, powered randomized controlled trials are needed to better define its efficacy.

Transient hypertrophic cardiomyopathy and hypertension associated with hydrocortisone in preterm infant: A case report.

RATIONALE: Hypertrophic cardiomyopathy (HCM) is a heterogeneous, usually familial disorder of heart muscle. The hypertrophic form of cardiomyopathy is frequently genetic, or as part of several neuromuscular disorders. In neonates, especially prematurity, HCM could also be secondary to corticosteroid treatment. PATIENT CONCERNS: We reported here a 34 weeks gestational age preterm infant presented with profound cardiomegaly after multiple doses of hydrocortisone used to treat blood pressure instability associated with septic shock and persistent pulmonary hypertension (PPHN). DIAGNOSIS: Patient presented auscultation of a grade III/IV harsh systolic ejection murmur from day 14, which was absent before. Profound cardiomegaly was indicated at chest film at day 30. Echocardiography showed severe thickening of the IVS (13.8 mm, z score = 8.29) and mild thickening of the posterior left ventricular wall (LVPW, 6 mm). INTERVENTIONS: Propranolol and captopril were started along with supportive care. The patient was also admitted to NICU for further treatment with 24-hour Holter electrocardiographic monitoring. OUTCOMES: A reversible course was observed without left ventricular outflow tract obstruction nor arrhythmias within 4 weeks. LESSONS: The risk/benefit ratio must be carefully considered when corticosteroids are used in prematurity. Monitors such as echocardiography and electrocardiograph should be conducted in order to guide cardiovascular management. Systematic surveys of the incidence of cardiac complications in a larger population of preterm infant treated with corticosteroid are needed in the future.

High gravimetric and volumetric sodium storage in a functionalized coal-based microcrystal/CNT binder-free electrode.

Abundant oxygen functional groups in coal-based microcrystals, especially for carboxylic anhydrides and quinone groups with two Na+ storage sites, provide plentiful active sites to adsorb Na+. The carboxyl groups serve as the binder connecting active material with a current collector. High gravimetric and volumetric sodium storage was achieved in this binder-free electrode.

Pseudocapacitive Na+ Insertion in Ti-O-C Channels of TiO2-C Nanofibers with High Rate and Ultrastable Performance.

Ti-O-C channels for ultrafast sodium storage were constructed in N/S-co-doped TiO2-C nanofibers, which deliver a high rate performance of 181.9 mAh g-1 at 5 A g-1 after 3000 cycles. The existence of Ti-O-C bonds at the interface of TiO2-C phases was revealed by synchrotron radiation X-ray absorption spectra. Based on this, first-principles calculations further verified the low energy barrier for Na+ insertion/extraction in the Ti-O-C channels formed by the intimately integrated graphite layer with TiO2 near the surface. In addition, surface defects induced by heteroatoms accelerate the Na+ mass transfer through the pathway from the carbon surface to the Ti-O-C channel.

Preparation and study of a new type of Fe-C microelectrolysis filler in oil-bearing ballast water treatment.

In the transportation of petroleum, large amount of oil polluted water will be produced, and the oil polluted water pumping into ocean will destroy ocean environment. To address oil-bearing ballast water, we fabricated a novel type of Fe-C microelectrolysis filler by using magnet powder, coconut shell biochar powder, bentonite, ammonium oxalate, and nickel powder. The COD and oil content removal efficiencies of 100 g/L oily wastewater were approximately 79.82% and 91.68%, respectively, after 100 min treatment at the following conditions: Fe-C mass ratio, 5:1; bentonite content, 20%; calcination temperature, 900 °C; calcination time, 2 h; ammonium oxalate content, 1.5%; and amount of nickel addition, 6.78%. The characteristics of the Fe-C microelectrolysis filler were analyzed. The surface structure of the filler was loose and porous, and its pores were developed. The Brunauer-Emmett-Teller (BET) surface area reached 49.4667 m2 g-1. A microelectrolysis filler is mainly mesoporous and contains large pores. Its average pore size is 2.6942 nm. Meanwhile, the results of our XRD analysis showed that some fillers were metal oxides, and most of them were simple metal substances.

Characterization of Xanthan gum-based hydrogel with Fe3+ ions coordination and its reversible sol-gel conversion.

Since redox-responsive hydrogels have a wide range of applications especially in biochemistry, such as drug release and biosensors, a kind of redox-responsive hydrogel was fabricated based on iron which has two stable oxidation states, while xanthan gum (XG) was selected as a matrix. In this work, characterization of XG-based hydrogel with Fe3+ ions coordination and its reversible sol-gel conversion property were studied. Xanthan gum solutions with different concentrations were coordinated in situ with constant trivalent iron ions concentration to form hydrogels under ambient temperature. The chemical features of XG-based hydrogels were characterized by Fourier transform infrared spectroscopy (FT-IR) and ultraviolet visible light spectrum (UV-vis), while scanning electron microscope (SEM) was used to observed the morphologies of XG-based hydrogels cross-sections. In addition, the mechanical properties, thermal stability and swelling behavior of xanthan gum hydrogels were also investigated, respectively. The results showed that xanthan gum hydrogels possessed relatively uniform layered structure, in addition to possessing enhanced mechanical strength and excellent swelling behavior. Furthermore, the sol-gel conversion of XG-based hydrogel could be realized by UV light in the presence of sodium lactate. The process of changes in viscosity was studied. The result indicated that the XG-based hydrogel could be recycled and these characteristic studies may be of reference for future use of xanthan gum hydrogels in the field of biomedical materials or sensors.

Selective detection of silver ions using mushroom-like polyaniline and gold nanoparticle nanocomposite-based electrochemical DNA sensor.

A highly sensitive electrochemical DNA biosensor made of polyaniline (PANI) and gold nanoparticles (AuNPs) nanocomposite (AuNPs@PANI) has been used for the detection of trace concentration of Ag(+). In the presence of Ag(+), with the interaction of cytosine-Ag(+)-cytosine (C-Ag(+)-C), cytosine-rich DNA sequence immobilized onto the surface of AuNPs@PANI has a self-hybridization and then forms a duplex-like structure. The whole detection procedure of Ag(+) based on the developed biosensor was evaluated by electrochemical impedance spectroscopy. On semi-logarithmic plots of the log Ag(+) concentration versus peak current, the results show that the prepared biosensor can detect silver ions at a wide linear range of 0.01-100 nM (R = 0.9828) with a detection limit of 10 pM (signal/noise = 3). Moreover, the fabricated sensor exhibits good selectivity and repeatability. The detection of Ag(+) was determined by Ag(+) self-induced conformational change of DNA scaffold that involved only one oligonucleotide, showing its convenience and availability.