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1.
Opt Express ; 32(9): 16426-16436, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38859269

ABSTRACT

Optical scattering measurement is one of the most commonly used methods for non-contact online measurement of film properties in industrial film manufacturing. Terahertz photons have low energy and are non-ionizing when measuring objects, so combining these two methods can enable online nondestructive testing of thin films. In the visible light band, some materials are transparent, and their thickness and material properties cannot be measured. Therefore, a method based on physical consistency modeling and machine learning is proposed in this paper, which realizes the method of obtaining high-precision thin film parameters through single-frequency terahertz wave measurement, and shows good performance. Through the experimental measurement of organic material thin films, it is proved that the proposed method is an effective terahertz online detection technology with high precision and high throughput.

2.
Nat Commun ; 15(1): 4426, 2024 May 24.
Article in English | MEDLINE | ID: mdl-38789507

ABSTRACT

Iron and phosphorus are essential nutrients that exist at low concentrations in surface waters and may be co-limiting resources for phytoplankton growth. Here, we show that phosphorus deficiency increases the growth of iron-limited cyanobacteria (Synechocystis sp. PCC 6803) through a PhoB-mediated regulatory network. We find that PhoB, in addition to its well-recognized role in controlling phosphate homeostasis, also regulates key metabolic processes crucial for iron-limited cyanobacteria, including ROS detoxification and iron uptake. Transcript abundances of PhoB-targeted genes are enriched in samples from phosphorus-depleted seawater, and a conserved PhoB-binding site is widely present in the promoters of the target genes, suggesting that the PhoB-mediated regulation may be highly conserved. Our findings provide molecular insights into the responses of cyanobacteria to simultaneous iron/phosphorus nutrient limitation.


Subject(s)
Bacterial Proteins , Gene Expression Regulation, Bacterial , Iron , Phosphorus , Synechocystis , Phosphorus/metabolism , Phosphorus/deficiency , Synechocystis/metabolism , Synechocystis/genetics , Iron/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Promoter Regions, Genetic/genetics , Seawater/microbiology , Homeostasis , Reactive Oxygen Species/metabolism
3.
Asian J Psychiatr ; 91: 103831, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37988928

ABSTRACT

OBJECTIVE: There seems to be an association between the DRD4 48-bp VNTR polymorphisms and antipsychotic treatment response, but there is a rare reference to confirm this finding. Hence, the present study tried to investigate the association between DRD4 48-bp VNTR polymorphisms and the treatment response of antipsychotics in patients with schizophrenia in Taiwan, using a propensity score matching (PSM) method. METHODS: A total of 882 participants were enrolled in this study and completed informed consent, research questionnaires, including demographic information and the revised Chinese version Beliefs about Voices Questionnaire, and blood sampling. For descreasing of the selection bias and confounding variables, the PSM nearest neighbor matching method was used to select 765 paitents with schizophrenia (ratio of 1:8 between 85 persistent auditory hallucination and 680 controls) with matched and controlled the age and gender. RESULTS: Schizophrenia patients with DRD4 4 R homozygosity had a lower rate of good antipsychotic treatment response than the other DRD4 genotype carriers (DRD4 non-4/4). Among those 4 R homozygosity carriers, 60 cases of 503 (11.9%) retain persistent auditory hallucinations. Furthermore, this subgroup of patients is accounted for up to 70.6% of cases with poor neuroleptic treatment response. CONCLUSIONS: A poor treatment outcome for patients with the 4 R homozygosity had presented,that comparing with those DRD non-4/4 genotype carriers. DRD4 VNTR 4 R homozygosity could be a genetic biomarker to predict poor antipsychotic treatment response in schizophrenia. Patients with DRD 4/4 probably receive novel antipsychotic medications preferentially or in combination with alternative therapy, such as psychotherapy or milieu therapy.


Subject(s)
Antipsychotic Agents , Schizophrenia , Humans , Schizophrenia/drug therapy , Schizophrenia/genetics , Antipsychotic Agents/therapeutic use , Receptors, Dopamine D4/genetics , Minisatellite Repeats/genetics , Genotype , Hallucinations/genetics , Hallucinations/drug therapy , Biomarkers
4.
Ear Nose Throat J ; 102(10): NP527-NP533, 2023 Oct.
Article in English | MEDLINE | ID: mdl-34134529

ABSTRACT

Malignant peripheral nerve sheath tumor (MPNST) is a rare tumor that can develop on the lining of nerves and within the network of nerve fibers in different organs, and it is commonly found in the head and neck, limbs, and trunk. These tumors can occur in patients of any age. They most commonly occur in adults aged 20 to 50 years; however, fewer cases of this tumor in children have been reported. To date, no neonatal case of MPNST in the nasal cavity has been reported. Here, we report the case of a 4-day-old female newborn who presented with a nasal mass that re-enlarged after surgery and was diagnosed as MPNST of the nasal cavity on the basis of pathological results. This is the first report of MPNST in the nasal cavity of a neonate. Differential diagnosis and treatment of nasal masses have been proposed in the related literature.


Subject(s)
Nerve Sheath Neoplasms , Neurofibrosarcoma , Adult , Child , Infant, Newborn , Humans , Female , Nerve Sheath Neoplasms/diagnosis , Nerve Sheath Neoplasms/surgery , Nerve Sheath Neoplasms/pathology , Nasal Cavity/pathology
5.
Eur J Clin Microbiol Infect Dis ; 42(1): 87-98, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36409375

ABSTRACT

The investigation on antibiotic stewardship in neonatal intensive care unit in China is scarce. This study aimed to analyze the effect of a comprehensive 2-year antibiotic stewardship in a level 4 NICU. During this baseline period from October 1st 2017 to October 1st 2019, continuation of empirical antibiotic therapy for ruled-out sepsis courses was beyond 72 h and for pneumonia was more than 7 days. Meropenem or vancomycin was used even if they were not the only bacterial sensitive antibiotics. The intervention period was from October 2nd 2019 to August 23rd 2021. Three areas for quality improvement were targeted in our center: discontinuation of antibiotic use in ruled-out sepsis within 72 h, treatment duration for culture-negative pneumonia less than 7 days, and vancomycin or meropenem was not used unless the cultured bacteria was only susceptible to them. The total antibiotic consumption decreased from 791.1 to 466.3 days of therapy per 1000 patient days from baseline to intervention period. Antibiotics were stopped within 72 h for 47.48% patients with rule-out sepsis and within 7 days for 75.70% patients with pneumonia compared with 11.56% and 37.69% during the baseline period respectively. The prevalence of multi-drug resistance bacteria decreased from 67.20 to 48.90%. The total use rate of meropenem or vancomycin decreased from 7.6 to 1.8%. Our quality improvement approach on antibiotic strategy significantly reduced antibiotic use and prevalence of multi-drug resistance bacteria in our NICU.


Subject(s)
Bacterial Infections , Sepsis , Infant, Newborn , Humans , Anti-Bacterial Agents/pharmacology , Vancomycin/therapeutic use , Intensive Care Units, Neonatal , Sepsis/microbiology , Meropenem/therapeutic use , Bacterial Infections/drug therapy , Drug Resistance, Multiple, Bacterial
6.
J Psychiatr Res ; 156: 698-704, 2022 12.
Article in English | MEDLINE | ID: mdl-36410308

ABSTRACT

Air pollution is a risk factor for increased hospital admissions due to mental disorders, while green spaces have been linked with better mental health. We linked daily hospital admission records from Wuhan's 74 municipal hospitals from 2017 to 2019 with modeled annual average NO2 concentrations and added data on the residential surrounding green spaces with 250 m and 500 m buffers based on the normalized difference vegetation index (NDVI) using a land use regression model (LUR). The conditional logistic regression model was used to estimate the acute effect of short-term NO2 exposure, and stratification analyses were applied to explore the modification effect of long-term NO2 exposure and green spaces by estimating the odds ratios in the single- and dual-environmental factor groups. A total of 42,705 hospital admissions for mental disorders were identified. Short-term exposure to NO2 was associated with an increased risk of hospital admission for mental disorders. A 10 µg/m3 increase in NO2 (lag01 day) was associated with an increase in hospital admissions of 2.86% (95% CI, 2.05-3.68) for the total mental disorders. Compared with patients in the "low-NDVI/low-NO2" group (ER = 2.27%, 95% CI, 0.27-4.31), patients in the "high-NDVI/low-NO2" group (ER = 1.93%, -0.10-3.99) showed a lower and insignificant increase in hospitalizations for the total mental disorders, while greenness had a slight moderating effect in the high-level long-term NO2 exposure areas. This study suggested that green spaces may moderate the acute effect of NO2 exposure for mental disorder hospitalizations, especially in low-level long-term NO2 exposure areas.


Subject(s)
Mental Disorders , Parks, Recreational , Humans , Mental Disorders/epidemiology , Mental Disorders/therapy , Hospitals
7.
ACS Omega ; 7(45): 40625-40637, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36406550

ABSTRACT

Hydrogen fuel cell vehicles have always been regarded as the main direction for developing new energy vehicles in the future due to their advantages of zero emission, high cruising range, and strong environmental adaptability. Currently, although the related technologies have gradually matured, there are still many factors hindering its development. One of the main reasons is that the price of hydrogen fuel increases the cost of using vehicles, which puts it at a competitive disadvantage compared with traditional fuel vehicles and pure electric vehicles. Herein, we summarize the recent development status of hydrogen fuel cell vehicles at home and abroad, and analyze the cost and sustainability brought by the latest scientific research progress to the hydrogen production industry, which is derived from basic research on electrocatalysts used in industrial electrocatalytic water splitting with an alkaline electrolyte. Finally, the development of hydrogen fuel cell vehicles was analyzed and prospected, which is one of the main application fields of hydrogen in the future.

8.
Inorg Chem ; 61(24): 9257-9268, 2022 Jun 20.
Article in English | MEDLINE | ID: mdl-35670559

ABSTRACT

We report the synthesis and characterization of a series of new open-framework iron fluoride-fluorophosphates based on linear, trinuclear, and tetranuclear chain FeIII building units. KFe2(PO3F)2F3 (I) consists of {Fe2(O3F)2F2}10- zigzag chains interconnected by P(O/F)4 tetrahedra forming a three-dimensional (3D) open framework. K2Fe(PO2.5F1.5)2F2 (II) is built up by {Fe(PO2.5F1.5)2F2}2- chains separated by K+ cation layers. The framework for K3Fe3(PO4)(PO3F)2F5 (III) contains two-dimensional {Fe3O4F4(PO3F)2}2- sheets, which are built from trimeric Fe-octahedra insulated by PO3F tetrahedra. The macroanionic framework of K3Fe4(PO4)2F9 (IV) comprises linear {Fe4O8F9}10- chains consisting of tetranuclear magnetic clusters of [Fe4O8F9]10- formed via corner-sharing fluorine atoms decorated with PO4 groups. The magnetic characterization of three iron fluorophosphates reveals diversified magnetism: S = 5/2 spin chains for I, antiferromagnetically coupled triangular Fe units for III, and coupled tetrahedral S = 5/2 spin chains for IV. IV shows strong geometric frustration thanks to its spin motifs of corner-shared tetrahedral clusters.

9.
Biomed Res Int ; 2022: 1530525, 2022.
Article in English | MEDLINE | ID: mdl-35281594

ABSTRACT

Biofilm formation is easily found in patients suffered from ventilator-associated pneumonia (VAP) in neonatal intensive care unit (NICU) and makes the VAP infections not only harder to be treated but easier to relapse. In order to find some novel ways to inhibit biofilm formation, this study describe a previously unrecognized role for the human umbilical cord mesenchymal stem cells (hUCMSCs). In addition to multiple differentiation, hUCMSCs have the ability to prevent the biofilms formation in vitro by secreting antibacterial peptides (LL-37 and hBD-2). This occurred while P. aeruginosa PA27853 and hUCMSCs were cocultured, and the filtrated medium, which was the supernatant containing antibacterial peptides (5.9 ng/ml of LL-37, 1.77 ng/ml of hBD-2), and inhibited the growth of the bacterial biofilm on the surface of tracheal tube (2.5#, for preterm infant). Using microarrays, we were able to demonstrate that the antibacterial peptides from hUCMSC affected biofilm formation by downregulating the gene-encoded polysaccharide biosynthesis protein. In addition, in order to find out the most suitable concentration of hUCMSCs, P. aeruginosa was cocultured with eight-level concentrations of hUCMSCs, and we found that the concentration of LL-37 was positively correlated with the concentration of hUCMSCs. Meanwhile, the concentration of LL-37 became stable while the hUCMSC concentration reaches higher than 5 × 106 cells/ml. But the concentration of hBD-2 had no significant correlation with hUCMSCs. The collection of these stem cells is not only limited by ethics but also reduces host rejection. This makes it possible to use autologous hUCMSCs to treat neonatal VAP.


Subject(s)
Mesenchymal Stem Cells , Umbilical Cord , Anti-Bacterial Agents/metabolism , Biofilms , Humans , Infant, Newborn , Infant, Premature , Mesenchymal Stem Cells/metabolism
10.
Huan Jing Ke Xue ; 42(10): 4807-4814, 2021 Oct 08.
Article in Chinese | MEDLINE | ID: mdl-34581123

ABSTRACT

Viruses in the aquatic environment have strong resistance to common disinfection techniques. To contribute to the development of efficient virus inactivation technologies, the characteristics and mechanisms of virus inactivation in a UV activated sodium persulfate(UV/PS) system were studied. The inactivation rate and kinetic characteristics of bacteriophage MS2 in water samples by the UV/PS were studied. The effects of PS dosage, pH, and the initial concentration of bacteriophages on the inactivation effect were also investigated. Furthermore, the morphologies of phages before and after UV/PS treatment were observed by transmission scanning electron microscope, and the free radicals in the reaction system were identified by electron paramagnetic resonance spectroscopy. By means of a free radical quenching experiment, the contribution rate of various factors in the UV/PS system to phage inactivation was also analyzed and calculated. The results showed that when the UV irradiation intensity was 160 µW·cm-2, the phage MS2 of 4.39 lg could be removed after UV/PS treatment for 4 min, which was 1.44 lg higher than that of the same UV dose alone. The inactivation of phage MS2 by the UV/PS system was in accordance with the first-order kinetic model. Increasing the initial concentration of PS in the system significantly improved the inactivation rate of phages, while pH and the initial concentration of phages had little effect on the inactivation rate. UV/PS treatment damages the capsid of phages and promotes the aggregation of phage particles. The presence of SO4-· and·OH in the UV/PS system was an important factor for the inactivation of MS2 phages. Finally, ·OH contributed more to MS2 phage inactivation than SO4-·.


Subject(s)
Levivirus , Water Purification , Sodium Compounds , Sulfates , Ultraviolet Rays , Virus Inactivation , Water
11.
Inorg Chem ; 60(17): 13707-13717, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34380318

ABSTRACT

Three new alkali-metal manganese fluoride selenates, A2Mn(SeO4)F3 (A = K, Rb, Cs), were prepared through hydrothermal redox reactions. The products consisted of one-dimensional polymeric anionic ∞[Mn(SeO4)F3]2- chains, where the A+ cations are connected by O and/or F atoms to form blocks with two-dimensional layers. A2Mn(SeO4)F3 (A= Rb, Cs) is isostructural with the monoclinic space group P21/c, while K2Mn(SeO4)F3 crystallizes in the orthorhombic space group Pbcn. A2Mn(SeO4)F3 (A = K, Rb, Cs) forms spin chains of Mn3+ with different Mn-F-Mn bridges, which showed canting antiferromagnetic behaviors. Single-crystal magnetic measurements revealed that the magnetic moments of the Mn ions were more canted for larger alkali-metal compounds in an antiferromagnetically ordered state.

12.
Inorg Chem ; 60(16): 12001-12008, 2021 Aug 16.
Article in English | MEDLINE | ID: mdl-34309359

ABSTRACT

Two M2(SeO3)F2 fluoro-selenites (M = Mn2+, Ni2+) have been synthesized using optimized hydrothermal reactions. Their 3D framework consists of 1D-[MO2F2]4-chains of edge-sharing octahedra with a rare topology of alternating O-O and F-F µ2 bridges. The interchain corner-sharing connections are assisted by the mixed O vs F anionic nature and develop a complex set of M-X-M superexchanges as calculated by LDA+U. Their interplay induces prominent in-chain antiferromagnetic frustration, while the interchain exchanges are responsible for the cycloidal magnetic structure observed below TN ≈ 21.5 K in the Ni2+ case. For comparison the Mn2+ compound develops a nearly collinear spin (canted) ordering below TN ≈ 26 K with ferromagnetic chain units.

13.
J Matern Fetal Neonatal Med ; 34(7): 1149-1154, 2021 Apr.
Article in English | MEDLINE | ID: mdl-32627623

ABSTRACT

OBJECTIVE: To investigate histopathological placental lesions and adverse neonatal outcomes by Pre-eclampsia (PE) with Gestational Diabetes Mellitus (GDM). METHODS: This was a retrospective cohort study of pregnancies with PE delivered between 1 January 2012 to 1 January 2014. Pregnant women with PE were recruited, and divided into PE with GDM (PE + GDM) group (n = 278) and PE without GDM (PE - GDM) group (n = 586). We compared the placental pathology and neonatal outcomes between the two groups. RESULTS: The (PE + GDM) group was significantly associated with high placenta weight (534.8 ± 124.1 vs 519.3 ± 132.3 g, p = .011), the large diameter of the placenta (17.8 ± 2.2 vs 16.2 ± 2.7 cm, p = .016) than (PE - GDM) group. The incidence of chorioamnionitis in (PE + GDM) group was significantly higher than (PE - GDM) group [48.9% (136/278) vs 41.5% (243/586), p = .028], whereas there were no significant differences in umbilical cord length and infarction between the two groups. The (PE + GDM) group had a higher rate of prematurity [44.9% (125/278) vs 39.9% (234/586), p = .042] than (PE - GDM) group, in (PE + GDM) group the incidence of LGA [15.1% (42/278) vs 1.0% (6/586), p = .034], RDS [18.7% (52/278) vs 9.2% (54/586), p = .011] and hyperbilirubinemia [10.7% (30/278) vs 1.0% (6/586), p = .038] were higher than (PE - GDM) group. CONCLUSIONS: GDM increased the offspring's complication in pregnancy with PE, the potential mechanism might be that GDM increased the placenta inflammation.


Subject(s)
Diabetes, Gestational , Pre-Eclampsia , Diabetes, Gestational/epidemiology , Female , Humans , Infant, Newborn , Placenta , Pre-Eclampsia/epidemiology , Pregnancy , Pregnancy Outcome/epidemiology , Retrospective Studies
14.
Biomed Res Int ; 2020: 1892458, 2020.
Article in English | MEDLINE | ID: mdl-33313310

ABSTRACT

OBJECTIVE: ANGPTL7 is a member of the angiogenin-like protein family. Compared to other members, ANGPTL7 is the least known. Recent studies have explored the relationship between ANGPTL7 and multiple pathological processes and diseases. However, there is no research about ANGPTL7 in neonates. This study was designed to investigate the concentration of ANGPTL7 in cord blood of preterm infants. METHOD: Singleton infants born in November 2017 to June 2019 in the study hospital were enrolled in the study. Maternal and neonatal clinical data were collected. ANGPTL7 levels in cord blood and serum on the third day after birth were measured by an enzyme-linked immunosorbent assay. RESULT: A total of 182 infants were enrolled in this study. Patients were categorized into two groups by gestational age (102 preterm, 80 full-term). ANGPTL7 levels in preterm infants were significantly higher than that in full-term babies (t = 15.4, P < 0.001). In multiple line regression analysis, ANGPTL7 levels independently correlated with gestational age (ß = -0.556, P < 0.001). There is also no correlation between preterm outcomes and ANGPTL7 levels. Cord blood levels of ANGPTL7 were significantly higher than those in serum on the third day after birth (t = 13.88, P < 0.001). CONCLUSION: Cord blood ANGPTL7 levels are higher in preterm infants than full-term babies. The levels are independently influenced by gestational ages and attenuated significantly after birth. The underlying mechanism needs to be further studied.


Subject(s)
Angiopoietin-like Proteins/blood , Fetal Blood/metabolism , Infant, Premature , Adult , Angiopoietin-Like Protein 7 , Enzyme-Linked Immunosorbent Assay , Female , Humans , Infant, Newborn , Male , Maternal Age , Mothers , Regression Analysis
15.
Water Sci Technol ; 82(11): 2472-2481, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33339800

ABSTRACT

Previous studies on the extraneous water problem (or infiltration/inflow) in sanitary sewer systems assumed that the wastewater flow is mainly composed of foul sewage (FS), groundwater infiltration (GWI) and rainfall-derived inflow and infiltration (RDII). Most existing assessment methods are based on this assumption. In 2018, China initiated the 'Protection of the Yangtze River Program', and the two-year research data showed that it was neither the GWI nor the RDII but the direct surface water intrusion (DSWI), which has rarely been reported in literatures, that serves as the main source of the extraneous water in many local sewer systems. The discovery has enriched the understanding of the extraneous water in sewer systems. Meanwhile, it brings new challenges for the assessment of extraneous water. In this study, starting from the analysis of the low influent concentration of chemical oxygen demand (COD) of the wastewater treatment plant in a southeastern city in China, a river water intrusion point was successfully localized and the volume of river water intrusion was quantified by a series of field experiments. The methodology used in this study can also be applied in other areas with DSWI.


Subject(s)
Rivers , Sewage , China , Cities , Wastewater , Water
16.
Chemosphere ; 254: 126851, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32957275

ABSTRACT

In this study, daily PM2.5 mass and chemical composition were measure in Lin'an Reginal Background Station, Yangzte River Delta, from March 1, 2018, to February 28, 2019. Organic matter (OM) was found to be the most dominant component in four seasons. The proportions of nitrate in PM2.5 presented dramatically lowest in warm seasons but highest in winter, indicating that NO3- was maily driven by thermodynamics. Regional transportation in winter plays a strong impact on PM2.5 concentration, which showed the highest average mass of 60.1 µg m-3. Sulfate occupied a significant portion of PM2.5 in summer (19%), followed by spring (17%), fall (15%), and winter (12%), respectively, suggesting photochemical processes may play a dominant role in the sulfate formation. Secondary inorganic aerosol (SIA) was the dominant component (70%) in the highest polluted periods (PM2.5 > 75 µg m-3), whereas OM decreased into the lowest fraction (22%) of PM2.5. Nitrate was the most important component in SIA in the highest polluted periods with regarding winter. Source apportionment results shown that winter haze was likely strongly dominated by SIA, which was mainly affected by air masses from the North China Plain and Shang-Hangzhou direction. PM2.5 is known to play an important role in sunlight absorption and reversing to human health, continuous observation on PM2.5 species in a background site can help us to evaluate the control policy, and promote our insights to lifetime, formation pathways, health effects of PM2.5.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring , Particulate Matter/analysis , Rivers/chemistry , Aerosols/analysis , China , Humans , Nitrogen Oxides/analysis , Seasons , Sulfates/analysis
17.
Article in English | MEDLINE | ID: mdl-32784870

ABSTRACT

To analyze the time-frequency characteristics of the particulate matter (PM10) concentration, data series measured at dry bulk ports were used to determine the contribution of various factors during different periods to the PM10 concentration level so as to support the formulation of air quality improvement plans around port areas. In this study, the Hilbert-Huang transform (HHT) method was used to analyze the time-frequency characteristics of the PM10 concentration data series measured at three different sites at the Xinglong Port of Zhenjiang, China, over three months. The HHT method consists of two main stages, namely, empirical mode decomposition (EMD) and Hilbert spectrum analysis (HSA), where the EMD technique is used to pre-process the HSA in order to determine the intrinsic mode function (IMF) components of the raw data series. The results show that the periods of the IMF components exhibit significant differences, and the short-period IMF component provides a modest contribution to all IMF components. Using HSA technology for these IMF components, we discovered that the variations in the amplitude of the PM10 concentration over time and frequency are discrete, and the range of this variation is mainly concentrated in the low-frequency band. We inferred that long-term influencing factors determine the PM10 concentration level in the port, and short-term influencing factors determine the difference in concentration data at different sites. Therefore, when formulating PM10 emission mitigation strategies, targeted measures must be implemented according to the period of the different influencing factors. The results of this study can help guide recommendations for port authorities when formulating the optimal layout of measurement devices.


Subject(s)
Air Pollution , Particulate Matter , Air Pollution/analysis , China , Particulate Matter/analysis
18.
Dalton Trans ; 49(28): 9751-9761, 2020 Jul 21.
Article in English | MEDLINE | ID: mdl-32618324

ABSTRACT

Four new alkali metal copper chlor-tellurites, [Cs(NH4)]layer[Cu4Te2O6Cl6]layer (I), [Rb3(NH4)2(OH)0.5]layer[Cu12Te6Cl16.5O18]layer (II), [K(NH4)]layer[Cu4Te2O6Cl6]layer (III) and [NaCl]layer[Cu4Te2O6Cl4]layer (IV), have been synthesized via hydrothermal reactions using mixtures of AF (A = Cs, Rb, K, Na), CuCl2·2H2O, TeO2, and hydrazine monohydrate. They have two-dimensional (2D)-layered [Cu4Te2Cl5+x-yO6]∞ (x = 0, 2/3, 1; y = 0, 1/6) structures that are separated by different layers comprised of various cations and anions, including A+, NH4+ Cl- OH-, etc. The blocks feature S-shaped ∞[Cu2O3Cl3-x] chains linked by TeO3 trigonal pyramids. The magnetic susceptibility shows a broad maximum at 220 K for I and 240 K for III, which is well simulated by using an alternating antiferromagnetic chain model. The J2/J1 ratio within the alternating chain is estimated to be 0.60(1), and the spin gaps are refined to be 152 K for I and 136 K for III.

19.
Inorg Chem ; 59(6): 3794-3804, 2020 Mar 16.
Article in English | MEDLINE | ID: mdl-32114764

ABSTRACT

Four transition-metal monofluorophosphates, with a chemical formula of Ba2M2(PO3F)F6 (M = Mn, Co, Ni, and Cu), have been synthesized hydrothermally using phosphoric and fluorophosphoric acids. The structures of Ba2M2(PO3F)F6 were intensively investigated by single-crystal and powder X-ray diffraction. Their networks exhibited three-dimensional frameworks formed by cis-MO2F4 octahedra and PO3F tetrahedra. Ba2M2(PO3F)F6 (M = Mn, Co, and Cu) are isostructural, crystallizing in the monoclinic space group P21/c, while Ba2Ni2(PO3F)F6 adopted an unpredetermined structure, crystallizing in the monoclinic space group P21/n. The different arrangements of the same cis-MO2F4 moieties and PO3F groups within one-dimensional chains lead to different frameworks in this late-first-row transition-metal series. By a comparison of normalized bond lengths with their normal counterparts, the more elongated octahedral cis-MO2F4 units in Ba2Cu2(PO3F)F6 reveal the presence of static Jahn-Teller distortion, uncovering the puzzling reason for the exceptional structure of Ba2Ni2(PO3F)F6 in the series. Ba2M2(PO3F)F6 (M = Mn, Co, and Ni) forms spin chains of M2+ made of coupled dimers or tetramers, showing dominant antiferromagnetic behavior.

20.
Dalton Trans ; 49(7): 2234-2243, 2020 Feb 21.
Article in English | MEDLINE | ID: mdl-32003383

ABSTRACT

A new oxofluoride Co15F2(TeO3)14 has been prepared by optimized hydrothermal synthesis involving a complex mineralization process. The crystal structure consists of a three-dimensional network of CoO5(O,F) octahedra, distorted CoO5 square pyramids, TeO3 trigonal pyramids and grossly distorted TeO3+3 octahedra, which are linked by sharing corners and edges. The Te(iv) lone pairs are accommodated within novel pyritohedron-shaped [(TeO3)14]28- units. This special framework provides a much larger free space that allows Te atoms to vibrate with a large amplitude, which leads to extremely low lattice thermal conductivity. Magnetic susceptibility data for Co15F2(TeO3)14 show antiferromagnetic ordering below 9.6 K with a substantial orbital component to the effective magnetic moment. An S = 3/2 honeycomb-like spin network was carefully analyzed by experimental techniques and first principles calculations.

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