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1.
Environ Res ; 247: 118158, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38224936

ABSTRACT

Existing wastewater treatment technologies face the key challenge of simultaneously removing emerging contaminants and nutrients from wastewater efficiently, with a simplified technological process and minimized operational costs. In this study, a novel alginate-embedded magnetic biochar-anoxygenic photosynthetic bacteria composite microspheres (CA-MBC-PSB microspheres) was prepared for efficient, cost-effective and one-step removal of antibiotics and NH4+-N from wastewater. Our results demonstrated that the CA-MBC-PSB microspheres removed 97.23% of sulfadiazine (SDZ) within 7 h and 91% of NH4+-N within 12 h, which were 21.23% and 38% higher than those achieved by pure calcium alginate-Rhodopseudomonas palustris microspheres (53% and 45.7%), respectively. The enhanced SDZ and NH4+-N removal were attributed to the enhanced photoheterotrophic metabolism and excretion of extracellular photosensitive active substances from R. Palustris through the photo-bioelectrochemical interaction between R. Palustris and magnetic biochar. The long-term pollutants removal performance of the CA-MBC-PSB microspheres was not deteriorated but continuously improved with increasing ruse cycles with a simultaneous removal efficiency of 99% for SDZ and 92% for NH4+-N after three cycles. The excellent stability and reusability were due to the fact that calcium alginate acts as an encapsulating agent preventing the loss and contamination of R. palustris biomass. The CA-MBC-PSB microspheres also exhibited excellent performance for simultaneous removal of SDZ (89% in 7 h) and NH4+-N (90.7% in 12 h) from the secondary effluent of wastewater treatment plant, indicating the stable and efficient performance of CA-MBC-PSB microspheres in practical wastewater treatment.


Subject(s)
Alginates , Charcoal , Wastewater , Microspheres , Sulfadiazine , Magnetic Phenomena
2.
J Environ Manage ; 356: 120726, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38537456

ABSTRACT

Electrochemical technology is a promising technique for separating ammonia from mature landfill leachate. However, the accompanying migration and transformation of coexisting pollutants and strategies for further high-value resourceful utilization of ammonia have rarely received attention. In this study, an electrochemical separation-Rhodopseudomonas palustris electrolysis cell coupled system was initially constructed for efficient separation and conversion of nitrogen in mature landfill leachate to microbial protein with synchronously tracking the transport and conversion of coexisting heavy metals accompanying the process. The results revealed that ammonia concentration in the cathode increased from 40.3 to 49.8% with increasing the current density from 20 to 40 mA/cm2, with less than 3% of ammonia transformation to NO2--N and NO3--N. During ammonia separation, approximately 95% of HM-DOMs (Cr, Cu, Ni, Pb, and Zn) were released into the anolyte due to humus degradation and further diffused to the cathode. A significant correlation was observed between the releases of HM-DOMs. Cu-DOMs accounted for 70.2% of the total Cu content, which was the highest proportion among the heavy metals (HMs). Among the HMs in anolyte, 57.4% of Pb, 52.5% of Ni, and 50.6% of Zn diffused to the cathode, and most of the HMs were removed in the form of hydroxide precipitations due to heavy alkaline catholyte. Compared with the open-circuit condition, the utilization efficiency of NH4+-N in the R. palustris electrolysis cell increased by 445.1% with 47% and 50% increases in final NH4+-N conversion rate and R. palustris biomass, respectively, due to bio-electrochemical enhanced phototrophic metabolism and acid generation for buffering the strong alkalinity of the electrolyte to maintain suitable growth conditions for R. palustris.


Subject(s)
Ammonia , Rhodopseudomonas , Water Pollutants, Chemical , Water Pollutants, Chemical/chemistry , Lead , Electrolysis , Waste Disposal Facilities , Nitrogen
3.
Opt Express ; 31(1): 301-312, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36606968

ABSTRACT

All-inorganic halide perovskite CsPbX3(X = Br/Cl/I)quantum dots have gained a considerable attention in the optoelectronic fields. However, the high cost and poor stability of the prepared CsPbX3 quantum dots (QDs) are inevitable challenges for their future practical applications. And the high-performance CsPbX3 QDs are always needed. Herein, a facile and low-cost synthesis scheme was adopted to prepare the CsPbBr3 QDs modified by lead bromide (PbBr2) and tetraoctylammonium bromide (TOAB) ligands at room temperature in open air. The prepared CsPbBr3 QDs exhibited a high photoluminescence quantum yield (PLQY) of 96.6% and a low amplified spontaneous emission (ASE) threshold of 12.6 µJ/cm2. Stable ASE intensity with little degradation was also realized from the CsPbBr3 QDs doped with PMMA. Furthermore, the enhanced ASE properties of the CsPbBr3 QDs-doped PMMA based on distributed feedback (DFB) substrate was achieved with a lower threshold of 3.6 µJ/cm2, which is 28.6% of that of the (PbBr2 + TOAB)-treated CsPbBr3 QDs without PMMA. This work exhibits a promising potential in the on-chip light source.

4.
Pestic Biochem Physiol ; 188: 105286, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36464339

ABSTRACT

The core elements of entomopathogenic nematode toxicity towards the fall armyworm Spodoptera frugiperda are associated with symbiotic bacteria. These microbes provide independent control effects and are reported to have repellency to insect pests. However, the ecological background of this nematode-bacteria-insect communication module is elusive. This work aims to identify key chemical cues which drive the trophic interactions through olfactory reception of S. frugiperda, and to inspire implementations with these isolated behavioral regulators in the corn field. A total of 657 volatiles were found within 13 symbiotic bacterial strains, and five of them induced significant electrophysiological responses of S. frugiperda larvae. 2-Hexynoic acid was demonstrated to exhibit a dominant role in deterring S. frugiperda larvae from feeding and localization. Field implementations with this novel volatile deterrent have resulted in fortified nematode applications. 2-Hexynoic acid acts as an excellent novel deterrent and presents remarkable application potential against fall armyworm larvae. Emissions from symbiotic bacteria of entomopathogenic nematodes are key players in chemical communication among insects, nematodes, and microbes. The olfactory perceptions and molecular targets for this volatile are worthy of future research.


Subject(s)
Bacteria , Nematoda , Animals , Larva , Spodoptera , Zea mays
5.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(7): 759-764, 2022 Jul 15.
Article in Zh | MEDLINE | ID: mdl-35894190

ABSTRACT

OBJECTIVES: To study the early clinical efficacy of combined therapy of stage 4 neuroblastoma. METHODS: A retrospective analysis was performed on the medical data and follow-up data of 14 children with stage 4 neuroblastoma who were diagnosed in Hong Kong University-Shenzhen Hospital from January 2016 to June 2021. RESULTS: The median age of onset was 3 years and 7.5 months in these 14 children. Among these children, 9 had positive results of bone marrow biopsy, 4 had N-Myc gene amplification, 13 had an increase in neuron-specific enolase, and 7 had an increase in vanilmandelic acid in urine. Based on the results of pathological examination, differentiated type was observed in 6 children, undifferentiated type in one child, mixed type, in one child and poorly differentiated type in 6 children. Of all the children, 10 received chemotherapy with the N7 regimen (including 2 children receiving arsenic trioxide in addition) and 4 received chemotherapy with the Rapid COJEC regimen. Thirteen children underwent surgery, 14 received hematopoietic stem cell transplantation, and 10 received radiotherapy. A total of 8 children received Ch14.18/CHO immunotherapy, among whom 1 child discontinued due to anaphylactic shock during immunotherapy, and the other 7 children completed Ch14.18/CHO treatment without serious adverse events, among whom 1 child was treated with Lu177 Dotatate 3 times after recurrence and is still undergoing chemotherapy at present. The median follow-up time was 45 months for all the 14 children. Four children experienced recurrence within 2 years, and the 2-year overall survival rate was 100%; 4 children experienced recurrence within 3 years, and 7 achieved disease-free survival within 3 years. CONCLUSIONS: Multidisciplinary combined therapy is recommended for children with stage 4 neuroblastoma and can help them achieve better survival and prognosis.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Neuroblastoma , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Child , Child, Preschool , Combined Modality Therapy , Humans , Infant , Neuroblastoma/drug therapy , Positron-Emission Tomography , Radionuclide Imaging , Retrospective Studies , Treatment Outcome
6.
Appl Opt ; 57(32): 9562-9570, 2018 Nov 10.
Article in English | MEDLINE | ID: mdl-30461736

ABSTRACT

Diode-pumped alkali vapor lasers (DPALs) have been rapidly developed because of their excellent performances. However, there have been few reports about DPALs with multiple wavelengths until now. The effects of the output features on the waist size and position of both Rb and Cs pump beams were first theoretically investigated using a kinetic model for an end-pumped dual-wavelength Rb-Cs laser. Then, a continuous-wave (CW) laser was experimentally constructed. Finally, the hybrid CW-modulated output with two wavelengths was also successfully obtained for the first time in development of alkali lasers. The results might be helpful in applications for laser communication and ranging/radar in the future.

7.
J Chem Phys ; 146(11): 114307, 2017 Mar 21.
Article in English | MEDLINE | ID: mdl-28330369

ABSTRACT

We report separate experimental and theoretical studies of the equilibration of highly excited LiH (v = 10; J = 2) in H2 at 680 K. Experiments that follow the time evolution of state-to-state population transfer in multi-collision conditions with µs resolution were carried out by Shen and co-workers at Xinjiang University and East China Institute of Science and Technology. At the same time, theoretical computations on the relaxation of this gas mixture were undertaken by McCaffery and co-workers at Sussex University. Rapid, near-resonant, vibration-vibration energy exchange is a marked feature of the initial relaxation process. However, at later stages of ensemble evolution, slower vibration-rotation transfer forms the dominant relaxation mechanism. The physics of the decay process are complex and, as demonstrated experimentally here, a single exponential expression is unlikely to capture the form of this decay with any accuracy. When these separate studies were complete, the evolution of modal temperatures from the Sussex calculations was compared with experimental measurements of these same quantities from Shanghai and Urumqi. The two sets of data were marked by their near identity, within experimental and computational error, representing an experimental validation of the theoretical/computational model developed by the Sussex group and a significant experimental advancement by the group of Shen et al.

8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(5): 1317-22, 2016 May.
Article in Zh | MEDLINE | ID: mdl-30000998

ABSTRACT

Degenerate stimulated hyper-Raman pumping is used to excite high vibrational states of NaH. The full state-resolved distribution of scattered CO2(0000, J) molecules from collisions with excited NaH(ν″=14, J=21) was reported. The nascent number densities of NaH were determined from absorption measurements at times t=1 µs as the laser to prepare NaH(ν″, J″). Absorption signals were converted to NaH(ν″, J″) population using absorption coefficients and the transient Doppler-broadened linewidths. The nascent CO2(0000, J) population were obtained from transient overtone laser induced fluorescence line intensity measured at short times relative to the time between collisions. The scattered CO2(0000, J=2~80) molecules had a biexponential rotational distribution. Fitting the data with a two-component exponential model yielded CO2 product distributions with Trot=(650±80) and (1 531±150) K. The cooler distribution accounted for 79% of the scattered population and resulted from elastic or weakly inelastic collisions that induced very little rotational excitation in CO2. The hotter distribution involved large changes in CO2 rotational energy and accounted for 21% of collision. Nascent translational energy profiles for scattered CO2 (0000, J=60~80) were measured using high resolution transient overtone fluorescence. The relative translational energy of the scattered molecules increased as a function of final CO2 rotational state with 〈ΔErel〉=582 cm-1 for J=60, and 2 973 cm-1 for J=80. Energy transfer rates were determined for the full J-state distribution by monitoring the change of the nascent population. The total rate constant for appearance of scattered CO2(0000) was kapp=(7.2±1.8)×10(-10) cm(3)·mol(-1)·s(-1). The depletion for the low-J CO2 states was involved in the collisional energy transfer of the initial distribution. For J=2~38, the average rate constant for depletion of scattered CO2(0000) is 〈kdep〉=(6.9±1.7)×10(-10) cm(3)· mol(-1)·s(-1).

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(11): 2887-91, 2014 Nov.
Article in Zh | MEDLINE | ID: mdl-25752025

ABSTRACT

Energy transfer rate constants were measured for excited rovibrational levels of Na2 (X1Σ(g)+). Stimulated emission pumping was used to excited the levels v = 33-51, J = 11 via A-X transition. Laser induced fluorescence was used to follow the collision dynamics. Energy transfer processes induced by collisions with Ar and H2 were investigated. The decay curves for the parent level populations gave good fits to single exponential function. At v = 33-51, the total transfer rate constants increase linearly with vibrational quantum number. Parameterized expressions for the (48, 11)--to--(47, J) rate constants were fitted to the fractional populations of the satellite lines. This produced sets of relative rate constants. Absolute rate constants were then obtained by normalizing the sums of the relative rate constants to the total removal rate constants. For Na2 (v) + Ar, no multiquantum vibrational transfer was detected. For Na2 (v) + H2, a significant fraction of the initial population of highly vibrationally excited Na2 (X v = 48) relaxes to lower vibrational level (Δ v = -5). The time scale is much shorter than the known collisional lifetimes of the intervening vibrational levels and thus a sequential single-quantum relaxation mechanism can be explicitly ruled out. For v = 48, at least 40% of the initially prepared population, undergoes multiquantum vibrational relaxation. We discuss possible explanations of this result.

10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(6): 1492-6, 2014 Jun.
Article in Zh | MEDLINE | ID: mdl-25358152

ABSTRACT

Energy transfer in H2 (1,1) +CO2 collisions was investigated using high resolution transient laser spectroscopy. Rotational state selective excitation of v = 1 for rotational level J = 1 was achieved by stimulated Raman pumping. Energy gain into CO2 resulting from collisions with H2 (1,1) was probed using transient absorption techniques, Distributions of nascent CO2 rotational populations in both the ground (00 degrees 0) state and the vibrationally excited (00 degrees 1) state were determined from overtone absorption measurements. Translational energy distributions of the recoiling CO2 in individual rovibrational states were determined through measurement of Doppler-broadened transient line shapes. A kinetic model was developed to describe rates for appearance of CO2 states resulting from collisions with H2(1,1). From scanned CARS (coherent anti-stokes Raman scattering) the spectral peaks population ratio n0/n1 was obtained, where n0 and n1 represent the number densities of H2 at the levels (0,1) and (1,1), respectively. Using rotational Boltzmann distribution of H2 (v = 0) at 300 K, n1 was yielded. Values for rate coefficients were obtained using data for CO2 (00 degrees 0) J = 48 to 76 and CO2 (00 degrees 1) J = 5 to 33. The rate coefficients derived from appearance of the (00 degrees 0) state have values of K(tr) = (3.9 ± 0.8) x 10(-11) cm3 x molecule(-1) x s(-1) for J = 48 and k(tr) = (1.4 ± 0.3) x 10(-10) cm3 x molecule(-1) x s(-1) for J = 76, with a monotonic increase for the higher J states. For the (00 degrees 1) state, values of k(tr) remain fairly constant at k(tr) = (4.3 ± 0.9) x 10(-12) cm3 x molecule(-1) x s(-1). Rotational populations for the nascent CO2 states were measured at 0. 5 µs following excitation of H2. The transient population for each state was fit using a Boltzmann rotational distribution. The CO2 (00 degrees 0) J = 48-76 rotational states were populated substantially relative to the initial 300 K CO2 distributions, and the distribution is described by Trot. The excited (00 degrees 1) state has T(rot), 310 K. The center-of-mass translational temperatures for the (00 degrees 0) state are all much greater than 300 K, with T(rel) = 1 532 K for J = 76. In contrast, transient line profiles for the J = 5 - 33 levels of excited (00 degrees 1) state do not show any broadening above the initial 300 K distributions, indicating that excitation to the (00 degrees 1) state is not accompanied by translational energy change.

11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(7): 1758-62, 2014 Jul.
Article in Zh | MEDLINE | ID: mdl-25269275

ABSTRACT

The vibrational levels of KH(X1 sigma+ v" = 0-3) were generated in the reaction of K(5P) with H2. The vibrationally excited KH(v" = 17) was populated by an overtone pump-probe configuration Different characteristics of collisional energy transfer in highly and lowly excited vibrational levels of KH and CO2 were investigated through measuring the time-resolved distribution of vibrational energy in KH(v" = 17.3) + CO2 collisions. For KH(v" = 17), there existed three principal regions of vibration temperature (T(v)) in this equilibration process. The initial phase consists of very rapid fall in T(v) within - 5 micros, and the vibrational energy of KH(v" = 17) is mainly transferred to the vibrational levels of CO2 (00 degrees 1) or high rotational levels of CO2 (00 degrees 0). The second phase (5-20 micros) has a slight decline in T(v), and the process of energy transfer to vibrational levels or high rotational levels of CO2 has already finished. The vibration temperature of the third phase has a slightly more rapid decline compared with the last phase. This phase shows that the process of transfer to lowly rotational levels and translation energy of CO2 is accelerated. The equilibration of vibrationally excited KH (v" = 3) in CO2 was also investigated. There are similarities to the behavior of KH (v" = 17) in CO2 plot, but also are significant differences. Once the initial resonant V-R exchange has equalized vibrational temperatures, there is a very slow linear decline in T(v) with equilibrium attained within -80 micros. This same point is reached within 15 micros for KH (v" = 17). The data demonstrate that single rate coefficient measurements are unlikely to capture the complex nature of processes that generally are multistaged with different relaxation rates characterizing each different stage. Examination of the quantum state distributions reveals that these distinct stages reflect the dominance of specific energy transfer mechanisms, some of which are inherently fast and others are much slower. The energy gain into CO2 resulting from collisions with excited KH was probed using transient absorption techniques. Distributions of nascent CO2 rotational populations in both ground (00 degrees 0) state and the vibrationally excited (00 degrees 1) state were determined. A kinetic model was developed to describe rate coefficients for appearance of CO2 states resulting from collisions with excited KH. These experiments show that collisions resulting in CO2 (00 degrees 0) are accompanied by substantial excitation in rotation while the vibrationally excited CO2 (00 degrees 1) state has rotational energy distributions near the initial distributions.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(4): 884-7, 2014 Apr.
Article in Zh | MEDLINE | ID: mdl-25007592

ABSTRACT

The radiative lifetimes and rate coefficients for deactivation of high lying 6(1)sigma+ state of NaK by collisions with H2 were studied. An OPO laser was set to a particular 2(1)sigma+ <-- 1(1)sigma+ transition. Another single mode Ti sapphire laser was then used to excite molecule from 2(1)sigma+ level to the 6(1)sigma+ state. The predissociation was monitored by the atomic potassium emission at the 3D --> 4P (1.7 microm) or the S --> 4P (1.24 microm), while bound state radiative processes were monitored by total fluorescence from the upper state to the various levels, all studied as a function of H2 density. The values for predissociation, collisional dissociation and collisional depopulation rate coefficients were obtained. The decay signal of the time resolved fluorescence from the 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ -->1(1)sigma+ or 2(1)sigma+ --> 1(1)sigma+ transition was monitored. Based on the Stern-Volmer equation, the radiative lifetimes were monitored for 6(1)sigma+ --> 2(1)sigma+ and 2(1)sigma+ --> 1(1)sigma+ transition. The rate coefficients for deactivation of collisions with H2 were monitored for 6(1)sigma+ --> 2(1)sigma+, 6(1)sigma+ --> 1(1)sigma+ and 2(1)sigma+ -->1(1)sigma+. When the density of H2 was 10(19) cm(-3), the total collisional transfer energy (15 426 cm(-1)) and radiative energy (10 215 cm(-1)) were obtained. The relative fraction ((f(v)), (f(R)), (f(T)) of average energy disposal was derived as (0.58, 0.03, 0.39); (f(v)), (f(R)), (f(T)) represent separately the relative fraction of average energy disposal among vibration, rotation and translation. The major vibrational and translational energy release supports the assumption that the 6(1)sigma(+) -H2 collision occurs primarily in a collisional energy transfer mechanism. In this experiment, alkali molecules relative energy population ratio was determined through using the time integrated intensity, so we can get the total transfer energy. That the NaK (6(1)sigma+) energy transfers to the H2 vibrational, rotational and translational energy was quantitatively given for the first time, which illustrates the collisional mechanism.

13.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124195, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38547782

ABSTRACT

The carbon dots (CDs) with excellent optical properties and their hydrogel complex are of great significance in biomedicine, healthcare and biochemical detection fields. This paper reports the preparation of green-emitting CDs (MA-CDs) through one-step hydrothermal route with citric acid as reducing agent, L-malic acid as carbon source and N-(2-hydroxyethyl)ethylenediamine as nitrogen source. To expand its application in biology, MA-CDs were coupled with vancomycin to obtain multifunctional CDs (VMA-CDs). The prepared VMA-CDs exhibit selective antibacterial behavior to Gram-positive bacteria, and it could be used as a fluorescent probe to selectively label Staphylococcus aureus (S. aureus). Moreover, thanks to the excellent optical properties of VMA-CDs, it has been used as a fluorescent sensor to detect Au3+ with detection range of 6.50 nM-21.93 µM and detection limit 3.98 nM. By introducing the fluorescence of CDs as the reference signal, and VMA-CDs as a response signal, the hydrogel (V-SP) was prepared and realized the detection of Au3+ in microfluidics with assistance of a smartphone to collect and analyze data.


Subject(s)
Hydrogels , Quantum Dots , Quantum Dots/chemistry , Carbon/chemistry , Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Fluorescent Dyes/chemistry , Nitrogen/chemistry , Spectrometry, Fluorescence
14.
J Adhes Dent ; 26(1): 79-86, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38465402

ABSTRACT

PURPOSE: This investigation aimed to assess the impact of additive manufacturing-generated surface textures on zirconia bond strength. MATERIALS AND METHODS: Zirconia samples (n = 144) fabricated using digital light-processing (DLP) technology were categorized into 6 groups according to the type of surface conditioning (group NN: no designs, no air abrasion; group NY: no designs, with air abrasion; group GN: groove designs, no air abrasion; group GY: groove designs with air abrasion; group HN: hexagon grid, no air abrasion; group HY: hexagon grid, with air abrasion). Composite resin cylinders were cemented to the treated zirconia surfaces with dual-curing, self-adhesive resin cement (Clearfil SA Luting). The shear bond strength (SBS) was tested after water storage for 3 days or 3 days with an additional 10,000 thermocycles. RESULTS: The zirconia samples fabricated using DLP technology have high accuracy. The SBS of the NY, GY, and HY groups did not significantly differ after 3 days, and neither did the SBS of the NN, GN, and HN groups. The NN, NY, and HY groups exhibited reduced SBS compared to their initial values following artificial aging, while the SBS of the remaining three groups were not diminished. The GY group obtained the highest SBS value after aging. CONCLUSION: Printing grooves with air abrasion can improve the bond strength.


Subject(s)
Dental Bonding , Air Abrasion, Dental , Surface Properties , Resin Cements/chemistry , Composite Resins , Shear Strength , Zirconium/chemistry , Materials Testing , Dental Stress Analysis
15.
J Hazard Mater ; 467: 133667, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38325102

ABSTRACT

Activated sludge extracellular polymeric substances (ASEPSs) comprise most dissolved organic matters (DOMs) in the tail water. However, the understanding of the link between the photolysis of antibiotic and the photo-reactivity/photo-persistence of ASEPS components is limited. This study first investigated the photochemical behaviors of ASEPS's components (humic acids (HA), hydrophobic substances (HOS) and hydrophilic substances (HIS)) separated from municipal sludge's EPS (M-EPS) and nitrification sludge's EPS (N-EPS) in the photolysis of sulfadiazine (SDZ). The results showed that 60% of SDZ was removed by the M-EPS, but the effect in the separated components was weakened, and only 24% - 39% was degraded. However, 58% of SDZ was cleaned by HOS in N-EPS, which was 23% higher than full N-EPS. M-EPS components had lower steady-state concentrations of triplet intermediates (3EPS*), hydroxyl radicals (·OH) and singlet oxygen (1O2) than M-EPS, but N-EPS components had the highest concentrations (5.96 ×10-15, 8.44 ×10-18, 4.56 ×10-13 M, respectively). The changes of CO, C-O and O-CO groups in HA and HOS potentially correspond to reactive specie's generation. These groups change little in HIS, which may make it have radiation resistance. HCO-3 and NO-3 decreased the indirect photolysis of SDZ, and its by-product N-(2-Pyrimidinyl)1,4-benzenediamine presents high environmental risk.


Subject(s)
Extracellular Polymeric Substance Matrix , Sewage , Sewage/chemistry , Extracellular Polymeric Substance Matrix/chemistry , Sulfadiazine/analysis , Anti-Bacterial Agents/analysis , Photolysis , Humic Substances/analysis
16.
Front Microbiol ; 14: 1168179, 2023.
Article in English | MEDLINE | ID: mdl-37303801

ABSTRACT

Introduction: The root-knot nematodes (RKN), especially Meloidogyne spp., are globally emerging harmful animals for many agricultural crops. Methods: To explore microbial agents for biological control of these nematodes, the microbial communities of the rhizosphere soils and roots of sponge gourd (Luffa cylindrica) infected and non-infected by M. incognita nematodes, were investigated using culture-dependent and -independent methods. Results: Thirty-two culturable bacterial and eight fungal species, along with 10,561 bacterial and 2,427 fungal operational taxonomic units (OTUs), were identified. Nine culturable bacterial species, 955 bacterial and 701 fungal OTUs were shared in both four groups. More culturable bacterial and fungal isolates were detected from the uninfected soils and roots than from the infected soils and roots (except no fungi detected from the uninfected roots), and among all samples, nine bacterial species (Arthrobacter sp., Bacillus sp., Burkholderia ambifaria, Enterobacteriaceae sp., Fictibacillus barbaricus, Microbacterium sp., Micrococcaceae sp., Rhizobiaceae sp., and Serratia sp.) were shared, with Arthrobacter sp. and Bacillus sp. being dominant. Pseudomonas nitroreducens was exclusively present in the infested soils, while Mammaliicoccus sciuri, Microbacterium azadirachtae, and Priestia sp., together with Mucor irregularis, Penicillium sp., P. commune, and Sordariomycetes sp. were found only in the uninfected soils. Cupriavidus metallidurans, Gordonia sp., Streptomyces viridobrunneus, and Terribacillus sp. were only in the uninfected roots while Aspergillus sp. only in infected roots. After M. incognita infestation, 319 bacterial OTUs (such as Chryseobacterium) and 171 fungal OTUs (such as Spizellomyces) were increased in rhizosphere soils, while 181 bacterial OTUs (such as Pasteuria) and 166 fungal OTUs (such as Exophiala) rose their abundance in plant roots. Meanwhile, much more decreased bacterial or fungal OTUs were identified from rhizosphere soils rather than from plant roots, exhibiting the protective effects of host plant on endophytes. Among the detected bacterial isolates, Streptomyces sp. TR27 was discovered to exhibit nematocidal activity, and B. amyloliquefaciens, Bacillus sp. P35, and M. azadirachtae to show repellent potentials for the second stage M. incognita juveniles, which can be used to develop RKN bio-control agents. Discussion: These findings provided insights into the interactions among root-knot nematodes, host plants, and microorganisms, which will inspire explorations of novel nematicides.

17.
Materials (Basel) ; 16(18)2023 Sep 05.
Article in English | MEDLINE | ID: mdl-37763350

ABSTRACT

Veneered zirconia ceramics are widely used for dental restorations. However, the relatively poor bonding strength between the ceramic core and veneer porcelain remains a common problem in clinical applications. To address this issue, this study focused on enhancing the core-veneer bond strength of zirconia restorations through the implementation of surface textures using digital light processing (DLP) technology. The light intensity was precisely tuned to optimize mechanical strength and minimize light scattering. Subsequently, hexagonal or square grids were printed on the surface of the zirconia ceramic core. Following veneering procedures, the shear bond strength (SBS) test was conducted using a universal testing machine. Dates were compared using analysis of variance (ANOVA) and the least significant difference (LSD) test. Furthermore, optical microscopy and scanning electron microscopy (SEM) were used to examine the failure modes and observe the cross-sectional structures, respectively. The results indicated that the presence of a 0.09 mm high hexagon grid led to a significant 21% increase in the SBS value. However, grids with heights of 0.2 and 0.3 mm showed less improvement, owing to the formation of large defects at the interface during the fusion process. This study demonstrated the potential of DLP technology in preparing zirconia ceramics with complex structures and high mechanical strength, thereby offering promising solutions for overcoming challenges associated with dental applications.

18.
Polymers (Basel) ; 15(5)2023 Feb 24.
Article in English | MEDLINE | ID: mdl-36904372

ABSTRACT

To avoid risk, spacecraft docking technologies can transport batches of different astronauts or cargoes to a space station. Before now, spacecraft-docking multicarrier/multidrug delivery systems have not been reported on. Herein, inspired by spacecraft docking technology, a novel system including two different docking units, one made of polyamide (PAAM) and on of polyacrylic acid (PAAC), grafted respectively onto polyethersulfone (PES) microcapsules, is designed, based on intermolecular hydrogen bonds in aqueous solution. VB12 and vancomycin hydrochloride were chosen as the release drugs. The release results show that the docking system is perfect, and has a good responsiveness to temperature when the grafting ratio of PES-g-PAAM and PES-g-PAAC is close to 1:1. Below 25 °C, this system exhibited an "off" effect because the polymer chains on the microcapsule's surface produced intermolecular hydrogen bonds. Above 25 °C, when the hydrogen bonds were broken, the microcapsules separated from each other, and the system exhibited an "on" state. The results provide valuable guidance for improving the feasibility of multicarrier/multidrug delivery systems.

19.
Anal Biochem ; 421(2): 368-77, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22056947

ABSTRACT

Protein kinases are recognized as important drug targets due to the pivotal roles they play in human disease. Many kinase inhibitors are ATP competitive, leading to potential problems with poor selectivity and significant loss of potency in vivo due to cellular ATP concentrations being much higher than K(m). Consequently, there has been growing interest in the development of ATP-noncompetitive inhibitors to overcome these problems. There are challenges to identifying ATP-noncompetitive inhibitors from compound library screens because ATP-noncompetitive inhibitors are often weaker and commonly excluded by potency-based hit selection criteria in favor of abundant and highly potent ATP-competitive inhibitors in screening libraries. Here we report the development of a time-resolved fluorescence resonance energy transfer (TR-FRET) assay for protein kinase cyclin-dependent kinase 4 (CDK4) and the identification of ATP-noncompetitive inhibitors by high-throughput screening after employing a strategy to favor this type of inhibitors. We also present kinetic characterization that is consistent with the proposed mode of inhibition.


Subject(s)
Adenosine Triphosphate/metabolism , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Fluorescence Resonance Energy Transfer/methods , Protein Kinase Inhibitors/pharmacology , Cell Line, Tumor , Chromatography, High Pressure Liquid , Cyclin-Dependent Kinase 4/metabolism , Humans , Kinetics , Mass Spectrometry , Models, Molecular
20.
Bioorg Med Chem Lett ; 22(1): 363-6, 2012 Jan 01.
Article in English | MEDLINE | ID: mdl-22123324

ABSTRACT

A series of spiropiperidine carbazoles were synthesized and evaluated as MCHR2 antagonists using a FLIPR assay. The pharmacokinetic properties of selected compounds have also been studied. This effort led to the discovery of potent and specific MCHR2 antagonists. Compound 38 demonstrated good pharmacokinetic properties across rat, beagle dog and rhesus monkey and had a favorable selectivity profile against a number of other receptors. These MCHR2 antagonists are considered appropriate tool compounds for study of the function of MCHR2 in vivo.


Subject(s)
Carbazoles/chemistry , Chemistry, Pharmaceutical/methods , Piperidines/chemistry , Receptors, G-Protein-Coupled/antagonists & inhibitors , Receptors, Pituitary Hormone/antagonists & inhibitors , Animals , CHO Cells , Cell Line , Cricetinae , Dogs , Drug Design , Humans , Inhibitory Concentration 50 , Macaca mulatta , Models, Chemical , Rats , Structure-Activity Relationship
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